CIVIC  SCIENCE 

IN  THE  COMMUNITY" 

HUNTER  AND  WHITMAN 


GIFT  OF 
Agriculture  education 


Our  modern  community,  with  all  its  beauty,  comforts,  and  conveniences,  has  gradually 
been  evolved  from  the  early  settlement  of  our  hardy  forefathers  through  the  appli- 
cation of  science  and  invention. 


CIVIC    SCIENCE 

IN   THE   COMMUNITY 


BY 
GEORGE  W.   HUNTER,  PH.D. 

PROFESSOR   OF   BIOLOGY,    KNOX   COLLEGE,   GALESBURG,    ILLINOIS 

FORMERLY  HEAD  OF  DEPARTMENT  OF  BIOLOGY,  DEWITT 

CLINTON   HIGH   SCHOOL,    NEW  YORK 

AND 

WALTER  G.  WHITMAN,  A.M. 

EDITOR,    GENERAL   SCIENCE   QUARTERLY 

THYSICAL  SCIENCE   DEPARTMENT,   STATE   NORMAL   SCHOOL 
SALEM,   MASSACHUSETTS 


AMERICAN   BOOK   COMPANY 

NEW  YORK  CINCINNATI  CHICAGO 

BOSTON  ATLANTA 


COPYRIGHT,  1922,  BY 
AMERICAN   BOOK  COMPANY 

All  rights  reserved 

H.-W       CIV.    SCI.   IN  COMM 
W,  P.  I 


MADE  IN  US.A. 


FOREWORD  TO  THE  TEACHER 

Man's  place  in  relation  to  science.  —  Living  things,  man  in- 
cluded, live  in  an  environment  which  is  made  up  of  certain 
definite  factors,  and  with  these  factors  living  things  react  and 
interact.  Some  of  these  factors  are  materials  —  things ;  other 
factors  are  forces.  The  ultimate  result  of  the  complex  we  call 
life  is  the  interaction  of  the  materials  and  forces  with  the  living 
things  on  the  earth.  Man,  however,  is  supreme  among  animals 
because  .of  all  the  animals  he  alone  can  control  the  factors  of 
his  environment.  He  has  control  of  fire  and  water  and  elec- 
tricity. His  home  has  evolved  from  the  cave  of  primitive  man 
to  the  complex  housing  systems  of  the  present  age.  His  com- 
munal life  has  brought  with  it  new  problems  —  the  disposal  of 
wastes,  the  safeguarding  of  water  and  milk  supplies,  the  need 
of  community  sanitation  and  hygiene.  His  higher  civilization 
demands  use  of  machines,  the  need  of  which  his  forefathers 
neither  knew  nor  felt ;  of  transportation  and  communication ; 
of  more  varied  and  practical  education  as  well. 

Children's  interests  in  science.  —  In  the  midst  of  such  a  life 
as  this  our  children  are  growing  up.  Science  beckons  to  them 
from  every  side.  In  every  device  used  at  home  for  comfort 
and  better  living,  science  speaks.  The  telephone  and  telegraph, 
the  trolley  and  the  automobile,  the  airplane  and  submarine,  have 
all  become  part  and  parcel  of  their  daily  lives.  Many  of  the 
common  things  of  science  which  directly  affect  the  lives  of  chil- 
dren are  equally  interesting  to  both  sexes.  But  in  any  scheme 
of  modern  education  we  must  take  individual  differences  into 
consideration.  We  no  longer  educate  in  the  mass.  Sex,  age, 
environment,  capability,  heredity,  all  are  important  factors 
which  must  be  recognized  by  the  modern  teacher  as  having  a 
place  in  educational  practice  as  well  as  theory. 


6  FOREVvORb  -T^'tHE  TEACHER 

The  project  method.  —  Since  we  must  allow  for  individual 
differences  in  our  scheme  of  education,  it  goes  without  saying 
that  mass  education,  which  does  not  account  the  child  as  a 
personality,  can  no  longer  be  admitted  as  a  part  of  our  scheme. 
We  must  take  cognizance  of  all  the  factors  mentioned  in  the 
last  paragraph ;  environment,  age,  and  sex  act  more  uniformly 
and  thus  may  be  taken  into  account  in  the  forming  of  classes 
or  groups.  But  individual  capability  and  endowments,  hered- 
ity's part  in  the  game  of  life,  are  much  more  difficult  factors  with 
which  to  deal.  Recent  developments  in  educational  psychology 
show  that  one  method  of  attack,  however,  has  certain  elements 
which  may  be  used  successfully  with  any  group  of  children  not 
too  young  to  think  to  a  conclusion.  Problem  solving  of  one 
sort  or  another  is  common  to  all  the  activities  of  life.  It  is  the 
one  great  factor  which  goes  toward  making  for  success  or  failure 
in  life.  It  should  be  part  of  the  mental  attitude  of  every  edu- 
cated person.  Problem  or  project,  call  it  what  you  will,  repre- 
sents the  method  by  which  things  worth  while  in  life  are 
achieved.  It  offers  the  pupil  a  method  for  accomplishing  those 
things  in  life  which  mark  off  greatness  from  mediocrity  —  the 
leader  from  the  led. 

Methods  in  science  adapted  for  children.  —  We  hear  a  good 
deal  nowadays  about  the  logical  versus  the  psychological 
approach.  No  teacher,  and  the  word  is  used  in  its  truest  sense, 
can  teach  except  from  the  viewpoint  of  the  child.  Approached 
from  this  angle,  the  psychological  becomes  logical.  We  must 
have  a  plan,  but  we  must  remember  that  a  plan  may  sometimes 
be  changed  to  advantage.  Above  all  we  must  be  human.  If 
we  but  remember  how  we  looked  at  things  with  the  eyes  of 
thirteen  instead  of  those  of  forty-three  we  will  have  no  difficulty 
in  solving  the  method  of  lesson  attack.  We  must  remember, 
too,  that  concepts  grow  and  are  not  always  brought  to  ma- 
turity in  one  lesson.  The  cyclic  treatment  of  topics,  which  has 
been  followed  in  Civic  Science,  is  a  far  more  natural  method  of 


FOREWORD   TO  THE  TEACHER  7 

acquiring  information  than  a  dogmatic  statement,  made  per- 
haps with  proof  but  dimly  comprehended  and  soon  forgotten. 
The  textbook  in  introductory  science.  —  Any  book  in  intro- 
ductory science  should  be  based  on  the  facts  we  have  just  men- 
tioned. It  must  contain  an  adequate  amount  of  the  basic 
material  from  which  the  interpretation  of  the  common  things 
of  interest  in  life  may  be  gained,  and  it  must  also  be  adapted 
to  start  the  individual  boy  or  girl  whose  interest  has  been  awak- 
ened along  the  line  of  the  project  in  which  this  developing  in- 
terest would  naturally  flow.  Most  of  all  a  textbook  should 
interpret  to  the  child  the  part  played  by  the  various  natural 
factors  in  his  environment.  It  should  conceive  the  child  as 
the  center,  and  all  the  world  of  the  child  revolving  around  this 
center.  In  this  conception  boys  and  girls  would  first  become 
aware  of  the  vital  part  played  by  air,  water,  light,  heat,  and 
food  on  them  as  individuals  within  their  homes.  After  the 
child  has  learned  the  meaning  of  these  central  factors  in  the 
home  the  next  step  would  logically  be  the  application  of  the 
forces  of  nature  by  man  in  communal  life.  In  short,  Civic 
Science  plans  to  lead  the  child  in  a  manner  which  is  both  logical 
and  psychological  from  the  simple  factors  which  make  up  his 
environment  as  a  living  thing  to  the  complex  combinations  and 
interactions  which  have  arisen  through  what  we  call  civilization. 
It  is  the  interpretation  of  this  complex  that  Civic  Science 
undertakes  with  the  belief  that  children,  if  given  a  rational 
point  of  view,  will  have  enough  varied  interests  to  build  on  the 
outline  which  follows.  They  will  thus  work  toward  the  solution 
of  those  things  in  science  which  seem  most  worth  while  to  them 
as  individuals  and  most  worthy  of  them  as  future  citizens. 

Purpose  of  this  work.  —  This  volume  is  intended  to  round 
out  some  of  the  science  information  previously  acquired  by  the 
pupil,  to  add  new  information  regarding  his  relations  to  his 
fellows,  and  through  its  point  of  attack  to  teach  good  citizenship, 
good  morals,  and  straight  thinking. 


8  FOREWORD  TO  THE  TEACHER 

Acknowledgments.  —  For  an  incentive  to  undertake  this 
work,  the  authors  are  indebted  to  those  educators  who  have 
written  much  on  the  subject  of  science  for  young  people,  par- 
ticularly, Thomas  M.  Balliet,  Thomas  H.  Briggs,  John  Dewey, 
Charles  W.  Eliot,  David  Snedden,  George  R.  Twiss,  and  John 
F.  Woodhull.  To  the  many  science  teachers  who  have  been 
active  in  developing  general  science  from  its. early  beginnings 
to  its  present  state,  the  authors  make  full  acknowledgment  for 
much  help  and  inspiration.  Acknowledgment  for  illustrative 
material  is  made  in  the  text.  The  drawings  were  nearly  all' 
made  by  Mr.  F.  M.  Wheat,  of  the  George  Washington  High 
School,  New  York.  The  following  teachers  have  carefully  read 
the  entire  proof  and  made  many  valuable  suggestions :  Mr. 
M.  C.  Leonard,  Vice-principal,  Dickinson  High  School,  Jersey 
City ;  Miss  A.  P.  Hazen,  Head  of  the  Department  of  Biology, 
Eastern  District  High  School,  Brooklyn;  and  Mr.  George  C. 
Wood,  Head  of  the  Department  of  Biology,  Commercial  High 
School,  Brooklyn;  and  also  Miss  Lydia  Holtman,  Knox  Col- 
lege, Galesburg,  111. 

REFERENCE  BOOKS 

Dewey,  How  We  Think,  especially  Chapters  IV,  V,  VI,  and  XV.  D.  C. 
Heath  Company. 

Flexner,  A  Modern  School,  New  York  Occasional  Papers  No.  3.  General 
Educational  Board,  New  York. 

Hunter,  Laboratory  Problems  in  Civic  Biology,  Foreword.  American  Book 
Company. 

Huxley,  Physiography.     Appleton  Company. 

Snedden,  Problems  of  Secondary  Education,  Chapter  XXI,  Houghton  Mifflin 
Company. 

Trafton,  The  Teaching  of  Science  in  the  Elementary  School,  especially  Chap- 
ter V.  Houghton  Mifflin  Company. 

Twiss,  Science  Tear-hing,  especially  Chapters  II,  III,  IV,  and  XIX.  The 
Macmillan  Company. 

Woodhull,  The  Teaching  of  Science.    The  Macmillan  Company. 


TABLE   OF   CONTENTS 

PAGE 

FOREWORD  TO  THE  TEACHER 5 

PART  I.   ADVANTAGES  OFFERED  BY  THE  COMMUNITY 

CHAPTER 

I.    THE  IDEAL  COMMUNITY       .        „,;.-:      .        .        .        .      n 
II.    How  THE  COMMUNITY  CAME  INTO  EXISTENCE  .        .       31 

III.  NATURAL  RESOURCES  OF  THE  COMMUNITY          ...      48 

PART  II.   WEATHER  AND  CLIMATIC  CONDITIONS 

IV.  THE  EFFECT  OF  CLIMATE  ON  COMMUNITY  LIFE         .        .      68 
V.    WEATHER  AND  THE  WEATHER  BUREAU       .        .        „       .      80 

PART  III.   WATER  AND  ITS  PLACE  IN  THE  LIFE  OF 
THE  COMMUNITY 

VI.  THE  RELATION  OF  WATER  TO  POWER         .        .     .  v    ^.     102 

VII.  THE  RELATION  OF  WATER  TO  FOOD  PRODUCTION      .        .115 

VIII.  THE  RELATION  OF  WATER   SUPPLY  TO   FORESTS        .        .128 

IX.  THE  COMMUNITY  WATER  SUPPLY 146 

PART  IV.    HOW  THE  COMMUNITY  CARES  FOR  ITS 
CITIZENS 

X.  ORGANIZATION  OF  A  CITY  GOVERNMENT      .        .        .        .    160 

XI.  How  THE  COMMUNITY  PROVIDES  FOR  PURE  FOOD      .        .170 

XII.  THE  PURE  FOOD  AND  DRUG  ACT  AND  How  IT  OPERATES   .     182 

XIII.  How  DISEASES  ARE  SPREAD  AND  How  TO  FIGHT  THEM     .    193 

XIV.  THE  RELATION  OF  INSECTS  TO  DISEASE     .        .        .        .203 
XV.  DISPOSAL  OF  WASTES  .        .        .        .        .        .        .224 

XVI.     STREET  LIGHTING 236 

XVII.     How  THE  COMMUNITY  SAFEGUARDS  LIFE  AND  PROPERTY  .  254 

XVIII.     ADVANTAGES  FOR  EDUCATION  AND  RECREATION          .        .  271 

9 


10  CONTENTS 

PART  V.  TRANSPORTATION  AND  COMMUNICATION 

CHAPTER  PAGE 

XIX.     GOOD  ROADS         ....        .        .        .        .        .  294 

XX.    TRANSPORTATION  BY  WATER 308 

XXI.     DEVELOPMENT  OF  LAND  TRANSPORTATION  .        .        .323 

XXII.    THE  AUTOMOBILE  AND  GASOLINE  ENGINE           .        .        .  338 

XXIII.  TRANSPORTATION  THROUGH  THE  AIR            .        .  .'  ,        .  353 

XXIV.  MEANS  OF  COMMUNICATION         .        .        .        .        »        .  367 

PART  VI.  HOW  LIFE  ON  THE  EARTH  HAS  IMPROVED 

XXV.    How  PLANTS  AND  ANIMALS  HAVE  BEEN  IMPROVED  .        .  386 

XXVI.     How  THE  HUMAN  RACE  HAS  PROGRESSED         ...        .        .  411 

INDEX  .  ......       .      >    i<        •        •       *    ; '.;     ,.       .  425 


PART   I.     ADVANTAGES   OFFERED 
BY  THE  COMMUNITY 

CHAPTER   1 
THE   IDEAL   COMMUNITY 

Problems.  —  i.  To  find  out  what  the  factors  of  my  en- 
vironment  are. 

2.  To  see  what  natural  advantages  my  home  community 
has. 

3.  To  find  out  what  man  has  added  to  nature  to  make  my 
community  a  good  place  to  live  in. 

4.  To  learn  how  I  can  help  make  my  community  a  better 
place  to  live  in. 

5.  To  understand  the  need  of  wise  laws  and  regulations 
in  the  community. 

Experiments.  — •  i.  To  learn  what  constitute  the  primary  factors  of 
our  environment. 

Project  I.  —  A  STUDY  OF  THE  ADVANTAGES  AND  DISADVANTAGES 

OF  MY  COMMUNITY. 

What  particular  advantages  does  my  community  enjoy  because 
of  favorable  factors  of  the  environment? 

What  disadvantages  make  the  community  unattractive  to  new- 
comers? Are  there  any  remedies? 

Project  II. — To  MAKE  AN  EXTENSIVE  SURVEY  OF  ONE  FACTOR 

OF  MY  ENVIRONMENT. 

Study  some  one  favorable  or  unfavorable  factor  of  the  environ- 
ment and  report  whether  full  advantage  is  being  taken  of  a  favor- 

ii 


11  THE   IDE \\.   COMMUNITY 

able  factor;  or  if  all  that  is  possible  is  being  done  to  change  an 
unfavorable  factor. 

Project  III. — To  MAKE  A  SURVEY  OF  MY  HOME  BLOCK,  LOCATING 

ALL   GOOD  AND   BAD   FACTORS    SO    AS    TO   TRY  TO    MAKE    IT   AN   IDEAL 
PLACE  IN  WHICH  TO  LIVE. 

What  is  most  important  for  a  community  ?  —  If  each 
member  of  the  class  were  asked  to  name  the  most  im- 
portant thing  to  have  in  the  community  where  he  or  she 
is  to  live,  we  should  be  likely  to  hear  a  great  many  differ- 


only  ruins  mark  the  place  where  the  thickly  populated  Greek  city  of  Paestum  once 
existed  in  southern  Italy.  Blocking  of  the  mouth  of  the  Silarus  with  silt  caused 
overflowing  of  the  banks  and  the  resulting  marshes  became  the  homes  of  count- 
less malarial  mosquitoes. 

ent  answers.  One  boy  would  say :  "A  nice  house  to  live 
in  "  ;  another,  "  Plenty  of  room  around  the  house,  so  that 
I  can  play  "  ;  still  another,  "  Vacant  lots  to  play  ball  in." 
A  studious  girl  might  say:  "  A  good  school."  Some  one 
might  say :  "A  healthful  place  to  live  in,"  and  this  perhaps 
is  the  best  answer  of  all,  for  of  all  the  important  things 
which  go  to  make  life  worth  while,  good  health  is  certainly 
the  most  important.  Many  a  city  of  ancient  Greece, 
once  adorned  with  beautiful  buildings  and  charming 


PURPOSE  OF  THIS  BOOK  13 

surroundings,  and  important  commercially,  had  its  in- 
habitants bitten  to  death  by  the  malarial  mosquito.  To- 
day those  cities  do  not  exist  except  as  interesting  heaps 
of  ruins.  Many  cities  of  our  South  and  Central  American 
neighbors,  as  well  as  our  own  southern  cities,  were  very 
unfavorable  places  to  live  in  before  it  was  discovered  how 
to  combat  the  dread  yellow  fever.  Location,  favorable 
opportunities  for  trading,  good  government  —  all  of  these 
would  mean  little  to  the  inhabitants  of  a  community  with- 
out good  health  to  enjoy  them,  and  good  health  depends 
upon  the  cooperation  of  every  one  in  the  community  as 
well  as  the  care  that  those  placed  in  control  exercise. 
As  one  writer  has  well  put  it :  "  Health  is  a  civic  obligation." 
Perhaps  the  best  indication  of  the  health  of  a  city  is  the 
physical  condition  of  its  school  children,  for  this  shows 
that  not  only  does  the  community  try  to  take  care  of  its 
young  citizens  but  that  they  in  their  turn  are  trying  to  do 
their  share  toward  promoting  good  health  in  their  town. 

Purpose  of  this  book.  —  Among  the  chief  purposes  of 
this  book  are:  first,  to  show  boys  and  girls  what  the. es- 
sential factors  are  which  make  a  community  a  good  place 
in  which  to  live;  second,  to  try  to  make  them  realize 
that  they,  as  the  future  leading  citizens  of  the  community, 
must  be  awake  to  their  opportunities  and  responsibilities. 
Boys  and  girls  have  cleaned  up  towns  and  made  them  fit 
places  in  which  to  live ;  boys  and  girls  have  helped  to  make 
the  fly  less  of  a  menace  to  health ;  they  have  helped  free 
our  towns  from  mosquitoes  because  they  were  well  in- 
formed and  well  read.  This  book  above  all  else  should 
show  the  boys  and  the  girls  of  the  average  community 
how  they  can  work  together  to  make  it  a  better  and  a  safer 
place  in  which  to  live. 


14  THE  IDEAL   COMMUNITY 

The  factors  of  environment.  —  We  have  already  learned 
what  the  factors  of  the  environment  are.  We  have  found 
that  air,  heat,  light,  water,  food,  and  the  soil  are  the 
necessities  which  living  things  must  have  in  order  to 
exist.  Each  of  these  factors  plays  an  important  part  in 


How  the  air  in  one  community  was  improved  when  a  smoke  consumer  was  installed  in- 
the  furnace  of  a  near-by  industrial  plant. 

the  life  of  every  individual.  They  play  an  equally  im- 
portant part  in  the  relation  of  one  person  to  another  in  a 
community. 

Experiment.  —  To   learn   what   constitute  the  primary  factors  of  our  en- 
vironment. 

Materials:  Some  wild  or  domestic  animal. 

Method  and  Observations:  What  is  a  factor  in  arithmetic  or  algebra? 
How  might  this  term  be  used  in  speaking  of  our  surroundings,  remem- 
bering that  environment  is  that  which  surrounds  us  and  gives  us  cer- 
tain materials  necessary  for  our  life?  Bearing  this  in  mind,  determine 
the  factors  in  the  environment  of  a  common  plant;  of  a  cat  or  dog; 
of  yourself.  Can  you  suggest  experimental  ways  to  prove  whether 
or  not  all  these  factors  are  necessary?  Now  compare  all  the  factors 
common  to  all  environments  to  see  which  are  the  common  factors. 

Conclusion:  What  are  the  primary  factors  in  environment  of  plants  and 
animals  ? 


WEATHER  15 

Air.  —  We  are  all  familiar  with  the  term  "  pure  air/' 
but  we  do  not  realize  always  what  pure  air  is.  The  boy 
or  girl  who  lives  in  a  big  city  where  much  soft  coal  is  used 
does  not  breathe  pure  air.  City  air  contains,  besides  dust 
and  bacteria,  a  considerable  quantity  of  carbon,  of  which 
we  all  become  aware  in  our  frequent  attempts  to  keep  our 
outer  clothing  clean.  Many  factories  and  industrial 
plants  produce  noxious  gases  which  make  living  near 
them  unpleasant  if  not  harmful.  Even  country  towns 
are  not  always  entirely  free  from  impure  air. 

Heat  and  temperature.  —  It  is  not  mere  chance  that 
most  people  live  in  temperate  climates,  nor  is  it  chance 
that  most  of  the  world's  activity  is  found  in  the  temperate 
zone.  Climate  plays  a  most  important  part  in  life.  Re- 
cent science  has  shown  that  the  most  efficient  work 
can  be  done  at  a  temperature  which  we  call  moderate ; 
that  is,  between  60  and  70  degrees  Fahrenheit.  As  a 
matter  of  fact,  most  great  scientists,  men  and  women 
prominent  in  the  world  of  art,  literature,  or  business,  have 
made  their  name  in  temperate  climates,  and  we  are  fortu- 
nate to  live  in  this  land  where  we  are  not  exposed  to 
extremes  of  temperature.  Our  ideal  community,  then, 
should  have  a  moderate  temperature  without  great  ex- 
tremes. 

Weather.  —  Favorable  weather  conditions  are  important 
factors  in  our  community  life.  Weather  conditions  are 
due  to  changes  in  the  atmosphere,  and  these  changes  are 
frequently  local.  We  may  have  excessive  rains  or  exces- 
sive dryness.  A  body  of  water  is  warmed  more  slowly 
than  an  equal  body  of  land  and  consequently,  at  night,  a 
breeze  may  come  in  from  the  water  to  the  land.  This 
accounts  for  the  cool  evening  breeze  which  so  frequently 


i6 


THE  IDEAL   COMMUNITY 


makes  life  bearable  in  a  hot  city  near  a  large  body  of  water, 
as  in  Chicago  or  New  York.  Another  weather  factor  is 
the  kind  of  prevailing  wind  we  have.  Westerly  winds 
prevail  in  the  wind  belt  in  which  the  United  States  is  sit- 
uated. One  part  of  the  United  States,  however,  is  sub- 
ject to  tornadoes,  and  we  all  know  there  is  a  storm  belt 
which,  in  a  general  way,  moves  from  west  to  east  across 


Along  the  lake  front,  Chicago. 

the  continent,  passing  off  the  Atlantic  coast  to  the  north- 
east. Very  strong  winds  might  be  of  importance  to  our 
community,  especially  if  much  damage  were  done  by  storms 
to  crops  or  buildings. 

Because  of  the  prevailing  westerly  winds,  the  rainfall 
in  the  western  part  of  the  United  States,  for  example,  on 
the  west  slope  of  the  Cascade  Mountains,  is  much  greater 
than  it  is  farther  inland.  This  is  simply  because  the 
wind,  loaded  with  moisture  from  the  ocean,  becomes 
cooler,  condenses  upon  striking  the  sides  of  the  moun- 


WEATHER  17 

tains,  and  then  gives  up  part  of  its  moisture  as  rain. 
This  explains,  in  part,  the  desert  conditions  in  the  south- 
western part  of  the  United  States,  for  there  the  winds  have 
to  pass  over  two  or  more  mountain  ranges  before  they 
reach  the  interior,  and  by  that  time  hardly  any  moisture 
remains  in  the  air,  consequently  little  or  no  rainfall  occurs. 
Locate  your  community  on  the  rainfall  map  and  decide 


Rainfall  map  of  the  United  States. 

whether  it  is  favorably  located  as  to  conditions  of  rainfall. 
Local  conditions,  such  as  forests,  wooded  hills,  small  ponds, 
also  help  to  equalize  climate  and  contribute  to  rainfall. 
Can  you  see  why?  Snow,  too,  would  have  to  be  consid- 
ered in  our  ideal  community  life.  Snow  gives  us  winter 
sports,  skiing,  coasting,  and  tobogganing.  It  keeps  the  soil 
in  good  condition.  In  lumbering  regions  it  is  of  much  use, 
as  the  logs  may  be  sledded  out  easily  to  places  where  they, 
can  be  sawed  into  usable  lumber.  On  the  other  hand  too 
much  snow  hinders  transportation  on  streets  and  railroads. 

H.  W.  CIV.  SCI.  COMM. 2 


i8 


THE  IDEAL  COMMUNITY 


Light.  —  Light  is  of  great  importance  to  health.  We 
live  in  a  temperate  zone  where  light  is  abundant,  and 
although  our  winter  days  are  shorter  than  those  of  summer, 
we  do  not  have,  as  the  Eskimo  does,  a  long  winter  night 
several  months  in  length.  In  addition,  we  have  artificial 
lighting.  One  of  the  factors  we  must  judge  our  community 
by  is  its  lighting  system.  Is  the  system  up-to-date  ?  Is  it 
sufficient  for  the  needs  of  the  community? 


Fine  winter  sport. 

Presence  of  water  routes.  —  Navigable  bodies  of  water 
are  also  of  very  great  importance  in  determining  the 
economic  standing  of  a  community.  Our  geography 
has  shown  us  that  most,  if  not  all,  important  cities  are  on 
navigable  rivers  or  other  bodies  of  water,  and  that  fre- 
quently they  are  at  the  ends  of  important  lines  of  communi- 
cation by  rail.  Examples  of  such  are  New  York,  with  its 
great  harbor  at  the  mouth  of  a  large  navigable  river,  Bos- 


WATER  POWER  19 

ton  and  Rio  Janeiro,  each  on  a  splendid  harbor,  Detroit, 
St.  Louis,  and  New  Orleans  on  fine  rivers,  Albany  and 
Pittsburgh  near  the  head  of  navigation  on  rivers.  The 
problems  of  transportation  and  communication  are  of  the 


New  York  harbor  from  Battery  Park 

utmost  importance  to  any  large  city,  and  many  com- 
munities owe  their  importance  to  the  fact  that  they  lie 
along  lines  of  communication  between  two  or  more  large 
terminal  cities. 

Water  power.  —  Water  power  on  a  river  is  also  a  factor 
in  the  determination  of-  the  location  of  a  town  or  city. 
Any  one  who  has  traveled  along  the  Merrimac  River  in 
Massachusetts  at  once  realizes  the  importance  of  water 
power;  in  the  Middle  West,  Minneapolis  is  a  city  using 
much  water  power.  Frequently,  in  olden  times,  a  mill  to 
grind  wheat  or  corn  might  have  been  placed  where  water 


20 


THE  IDEAL   COMMUNITY 


Shipping  along  the  water  front. 


Water  power  in  a  manufacturing  city. 


power  was  located,  and  as  the  people  of  the  neighborhood 
depended  upon  the  products  from  this  mill,  a  community 
would  gradually  develop.  Water  power  has  become  of 


THE  SOIL 


21 


great  importance  in  running  machines  for  factories  and  in 
producing  electricity.  Manufacturing  communities  have 
developed  on  sites  where  water  power  was  available. 

The  soil.  —  In  a  city,  soil  is  not  always  in  evidence. 
The  paved  streets  and  sidewalks,  sometimes  the  open 
squares  themselves,  show  little  signs  of  the  original  earth 
which  once  was  there ;  but  the  soil,  especially  in  some  com- 
munities, is  of  very  great  importance  in  determining  the 
healthfulness  of  the  place.  If,  for  example,  a  city  or 
town  is  built  upon  small  hills  composed  of  sand  or  gravelly 
soil,  drainage  will  be  good  and  probably  little  standing 


The  mosquito  menace  may  be  removed  by  draining  and  filling  a  swamp. 

water  will  be  found.     If,  on  the  other  hand,  the  town  has 
considerable  rock  underneath  it,  or  much  clay  or  other 


22  THE  IDEAL   COMMUNITY 

impervious  material,  the  drainage  is  not  likely  to  be  good 
and  much  standing  water  will  be  found.  If  a  city  or  town 
has  much  marsh  land  adjacent  to  it,  the  mosquito  problem 
may  become  very  grave  and  the  health  of  the  city  be 
menaced  by  malaria  or  yellow  fever.  Some  areas  covering 
limestone  are  particularly  useful  for  farming  districts. 

Sewage.  —  Among  the  problems  confronting  every  com- 
munity in  these  days  are  those  of  providing  some  means 
for  the  disposition  of  wastes  in  the  form  of  sewage,  and  of 
solid  wastes  such  as  garbage.  Large  cities  have  to  spend 
large  amounts  of  money  in  properly  disposing  of  these 
wastes.  In  some  cases,  such  as  we  have  mentioned  above, 
where  the  towns  have  natural  slopes  and  where  there  is 
some  body  of  water  into  which  to  drain  the  wastes  so  that 
they  may  be  carried  off,  the  disposal  of  sewage  is  a  com- 
paratively simple  matter,  but  sometimes  there  are  no 
rivers  or  oceans  to  drain  into  and  then  the  city  must  get 
rid  of  all  its  waste  by  means  of  a  disposal  plant. 

Garbage.  —  Garbage  disposal  is  also  of  very  great  im- 
portance for  the  health  of  the  city.  Garbage  pails,  if  left 
uncovered,  are  apt  to  become  breeding  places  of  flies,  and 
flies  are  carriers  of  disease.  One  of  the  problems  that  a 
community  has  to  face  is  properly  to  dispose  of  garbage. 
And  we  must  always  remember  that  cooperation  on  the 
part  of  everybody  is  necessary  if  our  community  is  to  be 
free  from  flies  and  diseases  carried  by  flies. 

Housing.  —  In  an  ideal  community,  every  family  lives 
in  a  detached  house  with  land  for  a  little  garden  and  a 
few  trees.  The  house  has  ample  ventilation.  Bedrooms 
have  two  windows  each  and  the  house  is  provided  with 
a  sleeping  porch.  Unfortunately  such  conditions  do 
not  prevail  in  a  large  city.  Not  only  do  we  have  rows 


PUBLIC   SUPPLIES 


upon  rows  of  closely  built  houses  with  little  or  no  space 
for  gardens  or  playgrounds  but  we  have  apartments  or  flats 
piled  one  on  top  of  another.  If  such  buildings  must  exist, 


What  are  the  advantages  and  disadvantages  of  these  two  types  of  houses  ? 

then  it  is  of  the  utmost  importance  to  the  health  of  that 
community  that  ample  ventilation  in  the  form  of  air- 
shafts  and  windows  be  provided.  The  ideal  community 
has  laws  regarding  such  ventilation  and  has  those  laws 
enforced. 

Public  supplies.  —  When  people  come  to  live   together 
there    are   certain   things  which  it  has  been   found   eco- 


24  THE  IDEAL   COMMUNITY 

nomical  to  control  in  common.  Water  supplies  and 
milk  supplies  are  of  this  nature.  An  ideal  community 
must  have  an  abundant  supply  of  pure  water.  Los 
Angeles  has  provided  its  inhabitants  with  over  200  gal- 
lons of  water  a  day  for  each  individual,  and  the  new 
aqueduct  of  the  city  of  New  York  brings  over  150  gallons 
daily  to  each  inhabitant.  The  source  of  the  water  must 


What  three  things  were  done  for  improvement  around  this  public  building  ? 

be  free  from  contamination,  so  that  pure  water  will  be  de- 
livered to  the  city.  If,  as  in  some  cases,  it  is  impossible 
to  get  pure  water,  the  water  supply  of  the  city  should 
be  safeguarded  by  means  of  a  filter,  sometimes  made 
of  huge  beds  of  sand  through  which  the  water  may  pass 
in  order  to.  remove  impurities.  In  addition  to  filtering, 
most  water  supplies  are  treated  with  certain  substances 
which  kill  any  organisms  harmful  to  health,  which  may 
be  in  them.  Milk  supplies,  although  sold  by  private 
concerns,  should  be  under  public  supervision  in  every  com- 


COMMUNITY  PLANNING 


munity.  Milk  is  one  of  the  most  important  factors  in  the 
health  of  the  babies  of  a  community,  and  upon  the  health 
of  the  babies  de- 
pends the  health  of 
the  future  inhabit- 
ants of  the  town. 

Community  plan- 
ning. —  No  city  or 
town  should  be  al- 
lowed to  grow  in  a 
haphazard  manner. 
The  streets  should 
be  well  planned  for 
the  future  growth 
of  the  community ; 
they  should  be  wide 
enough  for  all  traffic.  Parks  should  be  scattered  here 
and  there,  especially  in  the  poorer  sections,  for  people 
who  do  not  have  home  grounds  need  something  to  make 


Improving  the  environment  by  the  removal  of  signs. 


A  well-planned 


lanned  group  of  community  buildings,  in  which  are  shown  a  City  Hall,  Court 
House,  Post  Office,  Art  Museum,  Auditorium,  and  Community  Club. 

up  for  this  lack.  Playgrounds,  with  bathing  pools  and 
bathhouses,  ought  to  be  a  part  of  our  ideal  community's 
equipment.  Ugly  buildings,  billboards,  and  unkempt  vacant 


26  THE   IDEAL   COMMUNITY 

lots  ought  to  be  prohibited  by  law  and  the  community 
should  see  to  it  that  smoke,  dust,  and  unnecessary  noise 
are  reduced  to  a  minimum.  Lastly,  churches,  libraries, 
and  schools,  with  a  community  auditorium  and  stadium 
or  outdoor  theater,  ought  to  be  included  in  the  plan 
of  our  ideal  community. 

Community  government.  —  Laws  are  not  of  much 
value  unless  they  are  enforced.  A  community  govern- 
ment, first  of  all,  should  make  wise  laws  which  will  keep 
the  citizens  of  the  town  or  city  safe  and  healthy,  and 
then  it  should  enforce  these  laws.  A  city,  furthermore, 
must  have  several  departments  of  activity:  lighting  the 
streets,  taking  care  of  the  water  supply,  looking  after  our 
health,  protecting  our  homes  from  the  menace  of  fire; 
making  good  laws  and  having  a  police  force  to  see  that 
these  laws  are  kept.  The  work  of  the  department  of  health 
is  of  particular  importance.  This  department  should  not 
only  see  to  it  that  all  public  supplies,  such  as  water  and 
milk,  are  uncontaminated,  but  it  should  also  see  to  it 
that  laws  for  the  supply  of  pure  foods  are  made  and 
observed.  Fresh  foods  exposed  for  sale  should  be  cov- 
ered with  screens  or  placed  in  glass  cases.  Inspectors 
should  see  that  no  foods  are  sold  except  those  that 
are  fit  for  human  consumption  and  that  adulterants 
of  a  harmful  nature  are  not  allowed.  The  department 
of  health  should  require  all  cases  of  contagious  dis- 
eases to  be  reported.  Quarantine  laws  must  be  made 
and  enforced.  Epidemics  should  not  be  a  part  of  mod- 
ern life,  for  they  usually  occur  through  carelessness. 
Carelessness  must  not  be  allowed  in  the  ideal  commu- 
nity. Modern  methods  for  the  combating  of  disease 
should  prevail.  The  serum  treatment  of  disease  should 


SCHOOLS 


27 


be  given  free  in  all  cases  where  it  is  necessary.  Hos- 
pitals and  sanatoria  must  be  provided  for  various  dis- 
eases, and  each  city  or  community  ought  to  have  at  least 
one  hospital,  removed  from  the  town,  where  tuberculosis 
patients  could  have  the  best  care. 

Schools.  —  Fully  as  important  as  the  department  of 
health  and  perhaps  more  important  are  the  schools,  for  a 
modern  school  in  our  ideal  community  should  not  only 
teach  but  should 
take  care  of  its 
children.  Not  only 
should  hygiene  be 
taught  in  schools, 
but  there  must  be 
school  clinics  in 
which  to  examine 
and  care  for  the  teeth 
and  the  eyes,  the 
throats  and  the  noses 
of  school  children. 
In  addition  to  this, 
boys  and  girls  who 
go  to  school  can  do 
their  share.  They 
can  organize  sani- 
tary and  service 
squads,  the  mem- 
bers of  which  will  take  the  supervision  of  the  lunch  room 
and  see  that  boys  and  girls  observe  the  rights  of  others 
and  make  the  lunch  period  a  time  of  fun  but  not  of  an- 
noyance. They  can  help  in  the  morning  inspection  of 
pupils  by  acting  as  health  officers  in  their  own  individual 


The  school  nurse  helps  us  to  keep  well 


28 


THE  IDEAL   COMMUNITY 


divisions  or  classrooms.  They  can  all  work  together  to 
increase  the  school  spirit  for  better  living  and  better  work- 
ing conditions  in  the  schools  and  in  the  community. 

Use  of  the  score  card.  —  At  the  end  of  this  and  other 
chapters  in  the  book  is  found  a  score  card.  The  object 
of  this  card  is  to  compare  our  community  in  various 
ways  with  the  ideal  or  perfect  one.  Of  course,  if  we  are 
honest  with  ourselves,  no  matter  how  much  we  wish  to 
"  boost "  our  home  town,  we  shall  be  fair  in  our  scoring. 
Otherwise  there  is  no  value  in  the  exercise.  We  wish  to 
know  how  we  may  make  bad  conditions  better.  The 
score  card  should  show  up  the  weak  points  of  the  com- 
munity and  then  enable  us  to  improve  them.  In  making 
out  this  preliminary  score  card  or  survey,  copy  the  score  cards 
in  your  note  book,  put  your  estimate  down  in  the  column 
headed  "  My  Guess  Score  "  -  leave  the  column  headed 
"  My  Final  Score  "  blank  until  you  have  finished  your 
course  and  then  insert  the  scores  obtained  from  each  of  the 
individual  score  cards  made  out  from  time  to  time.  The 
last  estimate  will  show  how  far  your  guess  was  from  being 
a  true  estimate. 

GENERAL  SCORE  CARD  OF  MY  ENVIRONMENT 


PER- 
FECT 
SCORE 

MY 

GUESS 
SCORE 

MY 

FINAL 
SCORE 

NATURAL 
RESOURCES, 
ADAPTATION 
FOR  MAKING   A 
LIVELIHOOD 

Soil  adapted  to  cereal  crops  ....     (20) 
Soil  adapted  to  market  gardens      .     .     (20) 
Forests  give  opportunity  for  commu 
nity  business    (20) 
Land  suitable  for  grazing     _.     .     .          (20) 
Land  suitable  for  fruit  growing       .          (20) 
Presence  of  natural  waterways  .     .          (20^ 
Presence  of  ores  for  mineral  wealth          (20) 
Natural  fuels  abundant     ....          (20) 
Fish  sufficient  for  industry     .     .     .          (20) 
Selection  from  such  groups  as  offered 
by  your  community  not  to  exceed 

100 

100 

GENERAL  SCORE  CARD  OF  MY  ENVIRONMENT     29 


GENERAL  SCORE   CARD  OF  MY  ENVIRONMENT  —  Continued 


1 

PER- 
FECT 
SCORE 

MY 
GUESS 
SCORE 

MY  ' 
FINAL 
SCORE 

CLIMATE   AND 

Not  great  extremes  of  temperature     .     (20) 

No  danger   from  tornadoes  or  light- 
ning              (20) 

Freedom  from  hail,  early  frosts,  and 

No  long  periods  of  severe  heat  or  cold     (20) 

RELATION   OF 
WATER  TO 
PRODUCTION 

Water  power  gives  community  source 
of  business,  many   factories,  power 
cheap                     (60) 

Near-by  farms  well  watered  ....     (20) 

100 

COMMUNITY 
WATER   SUPPLY 

Water  from  pure  source     (20) 
Water  safe,  no  epidemics        ....     (10) 
Water  supply  safeguarded,  filtered       .     (10) 
Water  desirable,  soft,  no  color  or  taste     (20) 
Adequate  supply,  good  pressure       .     .     (20) 
Public  fountains  and  baths    .      .     .     .     (10) 
Cost  moderate     do) 

100 

COMMUNITY 

CARE   OF 

FOOD 

Milk  graded  and  pasteurized     .     .     .     (10) 
Inspection    of    meats    and    slaughter 
houses                                        .     .     .     (15) 

Inspection  of  groceries  and  stores  .     .     (15) 
Inspection  of  bakeries  and  products     .     (15) 
Inspection    of    restaurants    and    soda 
fountains,  proper  care  demanded     .     (15) 
Supervision  in  sale  of  patent  medicines 

IOO 

INSECTS   AND 
CITY 
CLEANLINESS 

No   breeding   places    for    mosquitoes. 
All  standing  water    entirely   elimi- 
nated or  protected  by   oil  or  intro- 
duction   of    fish.     No     mosquitoes 
present                                                      (50) 

If  culex  only  is  present,  score     .     .     .     (30) 
If  anopheles  is  present,  score      ...       (o) 
No  breeding   places  for    flies   found, 
manure  heaps  frequently  moved,  no 
open  privies,  no  rubbish  in  vacant 
lots,    screening   and    inspection    of 
markets,  no  flies                                 .     (50) 

Some  flies  but  not  annoying,  score      .     (30) 
If  flies  are  present  in  swarms,  score     .       (o) 

100 

WORK  OF 
BOARD   OF 
HEALTH 

Board  of  Health  active,  efficient,  well 
provided  with  equipment,  laws  en- 
forced on  quarantine  and  disinfec- 
tion,  free  antitoxins,   and  serums. 
Ample  hospital  equipment      .     .     .     (35) 
Law  enforcement  of  all  health  meas- 
ures and  cooperation  with  schools, 
homes,  and  civic  organizations    .     .     (35) 
Adequate  laws  with  reference  to  proper 
housing    conditions    are    enforced. 
Factories  and    stores   are   sanitary 
and  safe.    No  fire  traps      .     .     .     .     (30) 

IOO 

30  THE  IDEAL  COMMUNITY 

GENERAL  SCORE  CARD   OF  MY  ENVIRONMENT  —  Continued 


PER- 
FECT 
SCORE 

MY 
GUESS 
SCORE 

MY 
FINAL 
SCORE 

COMMUNITY 

Streets  well  lighted  at  night       .     .     .     (15) 
No  grade  crossings  ...                          (5) 

OF  LIFE  AND 

Efficient  police  system      (25) 

PROPERTY 

Efficient  fire  department  and  fire  laws 
and  regulations                                        (35) 

Traffic  laws  and  signals     (5) 
Cooperation  on  the  part  of  State  and 
Civic  organizations  in  protection  of 
life  and  property       (15) 

IOO 

ADVANTAGES 
FOR 
EDUCATION, 
RELIGION, 
SOCIAL  LIFE 
AND 
RECREATION 

School  system  compbte  and  adequate, 
having   elementary    (5),   secondary 
(5),    technical    (5),   normal   school 
or  college  (10),  special  schools  for 
deficients  and  defectives  (10)       .     .     (35) 
Free  library     (10) 
Churches,  active      (15) 
Social  agencies  active                                 (15) 

Museums,  concert  and  lecture  courses 
free     '.     (10) 
Public  parks,  playgrounds,  and  baths 
free  and  adequate      (10) 

Movies,    theaters,    and     recreational 
centers    (5) 

100 

TRANSPORTA- 
TION  AND 
COMMUNICA- 
TION 

Streets  well  paved  and  in-  good  repair, 
trees  abundant      (12) 
Roads   connecting   surrounding  com- 
munities well  paved  and  kept  in  re- 
pair   .                                                .     (15) 

Adequate   trolley,  jitney,  and  steam 
passenger  service       .......     (16) 
Adequate  freight  service   (12) 
Canal  or  other  water  transportation  .     (12) 
Air  transportation  developed      ...       (4) 
Parcel  post  and  mail  service  adequate     (12) 
Telegraph  and  telephone  (8) 
Fire  and  police  system       .     .     ;     .     .       (4) 
Daily  newspapers     (5) 

IOO 

GRAND  TOTAL      

IOOO 

REFERENCE  BOOKS 

The  American  City  Magazine.    Articles  of  mutual  interest  to  both  teachers  and 

students.     New  York. 

Farwell,  Village  Improvement.    (For  teachers.)     Sturgis  and  Walton  Company. 
Finch,  Everyday  Civics.    American  Book  Company. 

Forbush,  Young  Folks  Book  of  Ideals.    Lothrop,  Lee,  and  Shepard  Company. 
Geddes,  Cities  in  Evolution.     (For  teachers.)     Williams  and  Norgate. 
Howe,   The  Modern  City  and  its  Problems.     (For  teachers.)     Scribner. 
James,  Building  of  Cities.     The  Macmillan  Comnanv. 
Lewis,  The  Planning  of  the  Modern  City.     (For  teachers.)    John  Wiley  and  Sons. 


CHAPTER   II 

HOW  THE   COMMUNITY   CAME   INTO 
EXISTENCE 

Problems.  —  i.  To  learn  something  of  the  earth  as  a 
planet  and  of  its  early  history. 

2.  To  learn  how  the  earth  became  prepared  for  life. 

3.  To  learn  what  forces  are  constantly  at  work  changing 
the  earths  surface. 

4.  To  learn  about  the  life  of  early  man. 

5.  To  learn  how  community  life  began. 

Experiments.  —  i.  To  see  the  effect  rotation  (centrifugal  motion)  has 
upon  a  body. 

2.  To  see  if  natural  surface  waters  contain  soil  sediment. 

3.  To  learn  how  to  identify  a  few  common  rocks. 

4.  To  show  the  expansive  force  of  freezing  water. 

Project  I.  —  To  FIND  EVIDENCE  OF  EROSION  IN  OR  NEAR  MY  COM- 
MUNITY. 

Prepare  a  report  in  form  to  present  to  the  class. 

Project  II.  —  To  MAKE  A  COLLECTION  OF  LOCAL  ROCKS,  MINERALS, 
AND  SOILS. 

Learn  the  names  and  classification  of  as  many  as  possible.  Ar- 
range them  in  a  home-made  cabinet  properly  labeled. 

Project  HI. — TO  LEARN  THE  EARLY  HISTORY  OF  MY  COMMUNITY 
AND  TO  FOLLOW  ITS  DEVELOPMENT  UP  TO  THE  PRESENT  TIME. 

How  the  earth  became  inhabitable.  —  Any  boy  or  girl 
who  has  climbed  to  the  summit  of  a  hill  or  a  mountain 
knows  the  feeling  with  which  we  look  out  over  the  expanse 

31 


32     HOW  THE  COMMUNITY  CAME  INTO  EXISTENCE 

below.  We  are  alert  to  pick  out  this  or  that  familiar  land- 
mark, we  spy  out  forests  here  and  fertile  fields  there,  a  lake 
nestling  among  the  hills,  a  little  town  or  river  in  the  valley, 
perhaps  a  big  city  away  off  on  the  shore  of  some  large  body 
of  water.  We  have  that  feeling  of  elation  which  comes  to 
any  of  us  after  we  have  accomplished  something  worth 


We  view  the  mountains,  the  valley,  the  river  and  wonder  if  they  have  always 
existed  as  we  now  see  them. 

while,  and  we  feel  that  the  world  spread  out  below  us  is  a 
pretty  fine  place  to  live  upon,  after  all.  How  many  of  us, 
do  you  suppose,  think  back  into  the  distant  past  and  ask, 
"  How  did  all  these  wonders  of  mountain  and  plain,  hill  and 
valley,  river  and  lake,  rock  and  soil,  come  into  existence  ? 
Were  they  always  just  as  they  are  now  ?  Or  did  the  earth 
grow  and  change,  much  as  living  things  which  we  know  do  ?  " 


THE  EARTH  A  PLANET  33 

The  earth  a  planet.  —  Scientists  who  have  made  a 
careful  study  of  the  earth's  history  tell  us  that  it  was 
once  very  different  from  what  it  now  is.  We  remember 
that  the  earth  is  pictured  in  our  geography  as  a  nearly 
round  ball,  in  space,  moving  about  a  central  rotating  body 


A  nebula  from  which  new  bodies  like  the  earth  may  be  in  process  of  formation. 

called  the  sun.  Around  the  sun,  with  orbits  of  greater 
or  less  diameter,  are  other  planets,  some  smaller,  others 
much  larger,  than  this  earth  of  ours.  These  revolving 
planets,  moving  around  the  sun,  make  up  what  is  known 
as  the  solar  system.  When  we  remember  that  Mercury, 
the  planet  nearest  to  the  sun,  is  nearly  36,000,000  miles 
from  that  glowing  mass,  and  when  we  recall  that  Neptune, 
the  most  distant  planet,  is  2,780,000,000  miles  away  from 
the  sun,  our  brains  whirl  at  the  stupendous  figures  which 
astronomers  and  mathematicians  have  given  us.  Of  even 
greater  interest  than  these  enormous  figures  is  the  fact  that 

H.  W.  CIV.  SCI.  COMM.  3 


34     HOW  THE   COMMUNITY   CAME  INTO  EXISTENCE 


our  sun  is  only  one  of  many,  each  of  which  has  its  own  com- 
pany of  planets. 

How  the  earth  was  formed.  —  Scientists  believe  that 
this  earth,  and  probably  other  planets  as  well,  have  grown 
gradually  from  accumulation  of  solid  particles  from  space, 
or  have  been  evolved  from  gaseous  bodies  into  their  present 
form.  According  to  this  latter  view,  the  nebula  theory, 
the  entire  solar  system  was  a  mass  of  rapidly  whirling  gas. 
From  time  to  time  portions  of  this  gas  were  thrown  off  by 
centrifugal  action  and  in  time  each  mass  so  separated  be- 
came a  planet.  One  of  these  bodies  formed  from  a  detached 
fragment  of  the  sun  was  the  earth ;  thus  the  entire  earth 
was  at  one  time  in  the  form  of  hot  gases.  As  these  cooled, 
those  substances  which  form  the  solid  portion  of  the  earth 
condensed  and  solidified  first,  leaving  a  sur- 
rounding atmosphere  of  less  easily  condensed 
gases.  In  the  course  of  time  water  must 
have  come  from  the  atmosphere  by  condensa- 
tion as  the  earth's  surface  cooled  off.  You 
are  all  aware  of  the  condensing  of  moisture 
and  formation  of  rain  when  warm  moist  air 
is  cooled.  In  a  similar  way  did  the  rivers, 
lakes,  and  oceans  receive  their  supply  of 
water  from  the  atmosphere. 

Experiment.  —  To  see  the  effect  rotation  (centrifugal  mo- 
tion) has  upon  a  body. 

Materials:  A  one-liter  flask.    Colored  water.    Stout  cord. 
Method:  (i)  Pour  50  c.c.  colored  water  into  the  flask. 
Tie  a  cord  tightly  around  the  neck  and  suspend  it 
from  a  double  cord  four  feet  long.     This  suspension 
cord  must  be  fastened  to  the  flask  so  that  it  lies  in 
a  vertical  axis  running  through  the  center  of  the  neck  of  the  flask. 
Twist  the  cord  many  times  by  turning  the  flask.     When  left  free  the 
cord  untwists  and  the  flask  will  be  rotated  rapidly. 


EARLY  BELIEFS  35 

(2)  Repeat  (i)  using  a  flask  with  several  small  holes  blown  through 
the  walls  of  the  flask  at  the  level  of  its  greatest  diameter. 
Results  and  Conclusion:    What  happens  to  the  colored  water  in  (i)? 


What  effect  does  an  increase  in  speed  of  rotation  have  in  case  (2)  ? 
Application:   Apply  results  seen  here  to  explain  one  phase  of  the  action 
by  which  the  earth  was  formed  according  to  the  nebula  theory. 

The  age  of  the  earth.  —  Various  methods  have  been 
worked  out  by  scientists  to  determine  the  time  it  has  taken 
for  the  earth  to  assume  its  present  form.  One  way  is  to 
estimate  the  amount  of  salt  in  the  ocean  as  a  measure 
of  its  age.1  Assuming  that  the  water  was  originally  con- 
densed from  the  atmosphere  as  rain  the  time  it  would  take 
for  the  ocean  to  get  its  present  content  of  salt  from  the 
earth  could  be  computed  with  a  fair  degree  of  accuracy. 
The  latest  estimate  based  upon  this  method  makes  the 
oceans  a  little  less  than  100,000,000  years  old.  The  age 
of  the  earth  itself  must  be  much  greater.  Some  scientists 
estimate  up  to  400,000,000  years.  Its  present  surface 
form  is  due  to  the  forces  of  water,  air,  heat,  and  cold,  all 
working  to  carve  out  the  hills  and  valleys,  and  produce 
the  rivers  and  lakes  that  we  see  from  our  mountain  top. 

Early  beliefs.  —  The  early  beliefs  concerning  the  earth 
seem  rather  ridiculous  to  us  now.  When  we  remember 
that  as  late  as  the  time  of  Columbus  the  majority  of  edu- 
cated people  in  Europe  believed  that  the  earth  was  flat, 
and  that  the  sun  moved  around  it,  we  can  appreciate  the 
advances  made  later.  Copernicus,  a  native  of  northern 
Europe,  gave  out  in  1530  the  now  famous  belief  that  the 
sun  was  the  center  around  which  the  planets  moved.  This 
theory  was  slow  in  being  accepted,  but  half  a  century 
later  Galileo,  by  the  use  of  his  newly  invented  telescope, 

1  T.  C.  Chamberlain,  "  The  Evolution  of  the  Earth."     Scientific  Monthly,  1916. 


36     HOW  THE   COMMUNITY  CAME  INTO  EXISTENCE 


added  much  to  the  theory  of  Copernicus  and  helped  in  its 
establishment.  Still  later,  about  1660,  Sir  Isaac  Newton 
applied  his  discovery  of  the  law  of  gravitation  to  the  move- 
ments of  the  earth  and  other  planets.  The  familiar  story 
of  how  Newton  saw  in  the  dropping  of  an  apple  to  the 
ground  the  law  of  gravitation  is  one  which  every  boy  and 


. 


In  what  regions  on  the  earth  are  these  two  types  of  vegetation  found  ? 

girl  ought  to  know.  He  recognized  that  this  pull  of  the 
earth  upon  objects  was  a  universal  thing  and  could  be 
applied  as  a  law  to  other  planets  as  well.  The  attraction 
of  the  earth  for  bodies  near  its  surface  is  called  gravity. 
Gravity  causes  unsupported  bodies  to  fall  and  is  measured 
in  units  of  weight.  Gravitation  is  the  attraction  which 
any  one  body  in  the  universe  has  for  every  other  body. 
The  sun,  moons,  and  planets  in  the  solar  system  are  kept 
in  balance  by  this  attraction  of  gravitation. 


THE  EARTH  PREPARED  FOR  LIVING  THINGS      37 


Temperature.  —  The  effect  of  temperature  on  the  living 
things  upon  the  earth,  we  are  all  familiar  with  in  a  general 
way.  Geography  has  taught  us  something  about  the 
various  zones  of  life  upon  the  earth.  Temperature  is  the 
one  greatest  factor  in  determining  the  kind  of  life  found 
in  a  given  region.  The  lack  of  plant  life  in  the  arctic 
regions  and  the  wealth  of  vegetation  in  the  tropics  are  due 
largely  to  the  factor  of  temperature. 

How  the  earth  became  prepared  for  living  things.  - 
would  have  been  a  strange  world  that  would  have  met  our 
eyes  had  we  been  able  to  view  it  as  it  became  cool  enough 
to  sustain  life.   Proba- 
bly its  surface,  though 
very     irregular     and 
holding  bodies  of  water 
in  its  depressions,  was 
not  carved  into  moun- 
tain ranges  and  deep 
valleys  as  it  is  now. 
It     probably    looked 
very  much  as  the  sur- 
face of  the  moon  ap- 
pears to-day  through 
the  telescope.     It  was 
an  age  of  volcanic  ac- 
tion and  we   may  imagine   that  great  craters  or  active 
volcanoes  were   almost   everywhere  present.     These  vol- 
canoes, vents  from  the  superheated  interior  of  the  earth, 
poured  out  molten  rock  or  threw  off  with  the  heated  vapor 
masses  of  powdered  material  that  became  the  first  soil  of 
the  earth.     Bare  rocks  protruded  everywhere  in  a  chaos 
of  wildness,  broken  only  by  the  dark  sullen  bodies  of  water. 


A  portion  of  the  moon's  surface  seen  through  a  tele- 
scope.   Notice  the  craters  of  extinct  volcanoes. 


38     HOW   THE   COMMUNITY   CAME   INTO   EXISTENCE 


Surface  of  a  lava  flow. 


No  life  of  any  kind,  plant  or  animal,  could  be  seen.     It  was 

this  bleak,  lifeless  earth  that  has  been  transformed  into 

the  beautiful  veg- 
etation- covered 
world  that  we  know. 
How  were  all  these 
things  brought 
about  ? 

Rocks — what  are 
they  ?  —  Rock  is  a 
common  sight  to  all 
of  us.  We  see  it 
used  for  building 
purposes,  for  paving, 

both  in  the  streets  and  on  the  sidewalks.     Farmers  go  to 

some  trouble  to  remove  loose  rock  in  the  form  of  stones 

from  their  fields  and  build  them  into  walls      And  most 

of  us  know  that  if  we 

dig  into  the  earth, 

sooner   or   later  we 

shall  come  to  solid 

rock.      The     island  " 

of   Manhattan,    for 

example,  is  an  almost 

solid  mass  of  rock. 

ni  Twisted  gneiss  rock 

we  examine  such 

rock  closely,  we  see  it  is  twisted  or  contorted  as  if  it 
had  once  been  soft,  and  had  been  squeezed  together. 
This  would  seem  to  indicate  that  rock  was  once  molten 
or  at  least  soft.  The  first  rock  on  the  earth  was  of  this 
kind. 

Erosion  by  water.  —  Many  of  our  western  peaks  and 


EROSION  BY  WATER 


39 


the  mountains  of  Switzerland  are  huge  rock  masses  which 
are  being  slowly  worn  away  by  water.  If  we  were  to  go 
to  the  edge  of  a  rapidly  flowing  stream  in  Switzerland,  we 
would  notice  that  the  water  was  not  clear  but  had  a  muddy 
or  milky  appearance.  A  dish  of  such  water,  if  allowed  to 
stand  for  a  few  hours,  becomes  clear,  but  shows  a  large 
amount  of  sediment 
in  the  bottom  of  the 
dish.  Where  did 
this  material  come 
from  ?  Perhaps  a 
visit  to  the  boister- 
ous stream  at  a  point 
where  it  dashes  over 
the  rocks  will  answer 
our  question.  The 
force  of  the  water, 
tearing  loose  the 
strong  rocks,  rolls 
them  downstream 
one  against  another, 
and  finally  grinds 
them  into  powder. 
In  many  a  mountain 
valley  to-day  we  may 

See      this       powdered  A  gorge  formed  by  water  erosion. 

material  going  down  the  turbid  river.  Rock  particles  are 
carried  until  they  finally  reach  the  river's  mouth,  where  the 
current,  met  by  the  tide  from  the  ocean,  slows  up  and  the 
water  drops  its  load.  Thus  deltas  of  new  soil  are  formed. 
This  method  of  breaking  down  rock  into  soil  particles  is 
known  as  erosion.  Rivers  are  at  the  present  time  doing 


40     HOW  THE  COMMUNITY  CAME  INTO  EXISTENCE 

much  work  in  erosion.  Not  only  do  they  carry  away  the 
powdered  rock  particles  near  their  source,  but  they  are 
continually  wearing  away  the  material  from  some  part  of 
their  banks,  and  depositing  it  in  other  places.  Our  western 
rivers  are  yellow  with  mud  carried  from  the  treeless  plains 
through  which  they  flow. 

Experiment.  —  To  see  if  natural  surface  waters  contain  a  soil  sediment. 
Materials:  Glass  jars. 

Method:    A.   Collect  water,     i.   From  a  surface  puddle  after  a  rain. 
2.   From    a    swiftly    moving    brook    or    river    just    after    a  heavy 
rain.     3.   From  any  other  surface  water.     Let  these  stand  overnight. 
B.   Mix  soil  with  clear  water  by  stirring  in  a  glass  jar.     Allow  to 
stand  overnight. 
Results  and  Conclusion:  What  is  the  result  in  each  case? 

How  do  you  account  for  sediment  found  in  A?     What  was   its 
probable  source? 


Kinds  of  rock.  —  The  Mississippi  River  carries  millions 
of  tons  of  soil  to  the  Gulf  of  Mexico  every  year.  Enormous 
amounts  of  rock  sediment  are  brought  to  the  oceans  by  all 
large  rivers.  The  deposits,  in  time,  become  miles  in  depth 
and  the  lower  layers  are  subjected  to  tremendous  pressure 
and  heat.  As  a  result  the  particles  are  cemented  together 
into  rock.  In  this  way  sandstone  is  formed.  Rock  like 
sandstone,  which  was  formed  from  deposits  made  under 
water,  is  sedimentary  rock.  Because  this  shows  the  layers 
of  formation  it  is  also  called  stratified  rock.  Rock  like 
granite,  which  was  formed  by  cooling  from  a  molten  con- 
dition, is  igneous  rock.  All  the  rocks  of  the  earth  are  in, 
or  have  belonged  to,  one  of  these  two  classes.  A  rock  of 
either  class  may  undergo  a  change  of  partial  melting  and 
develop  new  crystals  and  a  different  appearance,  from  twist- 
ing, folding,  or  flowing.  It  is  then  called  metamorphic  rock. 
Gneiss,  slate,  and  marble  are  examples  of  metamorphic  rock. 


METHODS  OF  EROSION  41 

Small  amounts  of  rock  are  produced  by  deposit  from  water 
solution,  as  for  example  the  stalactite  of  limestone  caves. 


Granite,  an  igneous  rock. 


Gneiss,  a  metamorphic  rock. 


Experiment.  —  To  learn  how  to  identify  a  few  common  rocks. 

Materials:  Large  class  specimens  and  if  possible  small  hand  specimens 
of  granite,  sandstone,  limestone,  and  marble.  Dilute  hydrochloric 
acid. 

Method:  Observe  the  specimens  and  note  their  most  characteristic  prop- 
erties of  texture,  hardness,  luster,  etc.  Test  each  with  a  drop  of  acid. 

Results  and  Conclusion:  What  properties  may  serve  to  distinguish  one  of 
these  rocks  from  the  others? 

Methods  of  erosion.  —  It  is  common  knowledge  that 
heat  causes  substances  to  expand  and  occupy  more 
space,  while  cold,  on  the  other  hand,  causes  them  to 
contract.  When  water  freezes,  the  ice  formed  is  larger 
than  the  water  from  which  it  came.  Since  this  is  true, 
it  is  easy  to  see  that  when  water  gets  into  cracks  of 


42     HOW  THE   COMMUNITY   CAME   INTO   EXISTENCE 


rocks  and  freezes  there,  it  expands,  thus  forcing  the  rocks 
apart. 

Experiment.  —  To  show  the  expansive  force  of  freezing  water. 

Materials:  A  small  narrow-neck  bottle.  Stopper.  A  freezing  mixture 
of  salt  and  ice. 

Method:  In  freezing  weather  each  pupil  may  fill  a  small  vial  with 
water.  Close  it  with  a  stopper  and  place  it  out  of  doors  when  the 
thermometer  reads  below  32°  F.  In  warm  weather  a  bottle  full  of 
water  is  closed  with  a  stopper  and  packed  in  alternate  layers  of  crushed 
ice  and  salt.  After  a  time,  depending  on  the  size  of  the  bottle,  examine. 

Result  and  Conclusion:  When  the  water  has  completely  changed  to  ice 
what  other  change  do  you  find  accompanied  the  freezing  ? 

Application:  What  is  the  application  of  this  to  soil  making? 


The  hot  rays  of  the  summer's  sun  melt  the  ice  on  the  high 


mountains  during  the 
day.  At  night  the 
water  freezes  again, 
and  this  process,  kept 
up  day  after  day, 
eventually  cracks  the 
hardest  rocks.  Run- 
ning water  moves 
sand  and  gravel  over 
rocks,  wearing  them 
down.  A  large  mass 
of  moving  ice,  as  a 
glacier,  is  a  powerful 
agent  of  erosion. 
The  Alpine  glaciers 
gather  rock  frag- 
ments from  the  sides 
and  bottoms  of  the 
valleys.  These  frag- 
ments become  grind- 


An  Alpine  glacier.    See  the  three  streams  of  rock 

fragments  torn  from  the  sides  of  the  valleys. 

(After  Cleland.) 


CHANGES  IN  ROCK  MATERIAL 


43 


ing  tools,  moved  under  tremendous  pressure  of  the  ice,  and 
cut  away  more  rock  while  they  in  the  end  are  worn  to  fine 
particles.  Rock  thus  grinds  against  rock  so  that  by  the 
time  the  valley  is  reached  both  may  be  ground  to  powder. 
Thus  many  of  the  streams  issuing  from  the  foot  of  gla- 
ciers are  white  with  the  rock  dust  or  sediment  carried 
away  by  them. 

Erosion  by  wind.  —  In  many  parts  of  the  world,  the  wind 
plays  an  important  part  in  soil  making.  You  have  all 
seen  a  sand  blast, 
and  have  noticed 
that  the  tiny  parti- 
cles of  sand,  driven 
by  a  current  of  air 
against  the  outer 
surface  of  a  build- 
ing, will  in  a  very 
short  time  change 

Erosion  by  wind-driven  sand. 

the    appearance    of 

its  surface.  In  some  parts  of  the  West  the  wind  drives 
millions  of  particles  of  sand  against  the  sandstone  cliffs  or 
buttes  with  such  force  that  they  are  worn  down  and  hol- 
lowed out  by  this  natural  "  sand  blast." 

Changes  in  rock  material.  —  We  have  thus  found  that 
rocks  which  in  their  original  form  may  have  been  either 
molten  volcanic  matter  or  formed  by  slow  deposition  of 
material  under  water,  may  be  broken  down  to  form  soil 
in  several  different  ways..  First,  water  may  wear  away 
rocks,  and  then  deposit  the  ground-up  material  as  inorganic 
soil.  Second,  rocks  may  be  cracked  up  under  the  alternate 
action  of  heat  and  cold.  Third,  glaciers,  or  rivers  of  ice, 
may  transport  the  fragments  of  rocks  which  are  broken 


44     HOW  THE  COMMUNITY  CAME  INTO  EXISTENCE 

off  by  the  action  of  frost  or  heat,  and  grind  them  into 
soil.  Fourth,  the  wind  may,  by  driving  particles  against 
the  rocks,  have  an  eroding  effect  upon  them. 

What  is  soil?  —  Soil,  then,  in  its  original  form,  is  ground- 
up  or  powdered  rock.  The  character  of  the  soil  depends 
upon  the  kind  of  rock  from  which  it  is  produced  Sand, 
for  example,  is  rather  coarse  material  containing  usually 
a  good  deal  of  silica.  Clay,  on  the  other  hand,  is  very  finely 
ground-up  rock,  and  may  be  of  various  colors,  depending 
upon  the  mineral  substance  with  which  it  is  impregnated. 
Such  soil  is  inorganic,  and  is  without  living  material  of 
any  kind.  But  soil,  after  plants  and  animals  appeared  on 
the  earth,  became  made,  in  part  at  least,  of  their  dead 
forms.  The  addition  of  organic  matter,  derived  from 
dead  animals  and  plants  or  products  of  these,  to  the 
inorganic  soil  makes  the  rich  black  soil  we  call  loam.  After 
the  earth  became  covered  in  part  with  soil,  water  in  the 
form  of  rivers  or  streams  began  to  play  an  important  part 
in  changing  its  appearance.  Rivers  cut  their  way  through 
its  surface  and  to-day  in  places  where  the  natural  protec- 
tion of  living  plants  has  been  removed,  the  forces  of  ero- 
sion are  doing  their  work  very  swiftly,  because  water,  wind, 
heat,  and  cold  act  more  quickly  upon  unprotected  soil 
and  rock. 

The  coming  of  life  on  the  earth.  —  Just  how  and  when 
life  came  on  the  earth  we  do  not  know.  It  must  have 
been  a  good  many  millions  of  years  ago.  Probably  at  first 
the  water  became  the  home  of  tiny  one-celled  plants  and 
possibly  animals  as  well.  And  as  time  went  on  more  and 
more  complex  forms  of  life  came  into  existence.  Perhaps 
some  day  you  will  take  up  the  study  of  that  fascinating 
subject,  geology,  which  treats  of  the  rocks  and  their  forma- 


THE  LIFE  OF  EARLY  MAN 


45 


tion.  In  these  rocks  we  frequently  find  fossils,  remains 
or  traces  of  plants  or  animals  which  lived  upon  the  earth 
in  former  ages.  By 
means  of  a  study  of 
these  fossils  which 
are  embedded  in  dif- 
ferent kinds  of  rocks 
and  at  different 
depths,  we  have  been 
able  to  form  quite  a 
definite  history  of 
the  development  of 
life  upon  the  earth. 
We  know  that  as  life 
on  the  earth  devel- 
oped, plants  and  ani- 
mals became  more 
and  more  complex, 
until  finally  animals 
of  a  type  found  upon  the  modern  earth  came  into  being, 
and  at  last  man. 

The  life  of  early  man.  —  Think  of  a  world  without  any 
modern  conveniences,  without  homes,  without  even  fires. 
But  such  was  the  world  of  primitive  man.  He  was  a  wan- 
derer and  lived  like  the  wild  beasts  which  preyed  upon  him 
and  which  he  killed  with  his  own  hands  for  food.  At  first 
these  people  probably  lived  in  caves,  and  we  can  imagine 
how  the  discovery  of  fire  must  have  added  to  their  comfort 
as  well  as  their  safety.  They  must  have  been  skilled  hunters, 
for  piles  of  bones  have  been  found  near  their  ancient  camps. 
Gradually  they  must  have  learned  to  use  implements  as 
well  as  weapons,  made  earlier  of  stone  and  later  of  bronze 


Rock  bearing  fossils 


46     HOW  THE   COMMUNITY   CAME  INTO  EXISTENCE 


and  iron.  Then  came  the  discovery  that  the  seeds  of  cer- 
tain wild  grasses  were  good  to  eat.  When  grains  began  to 
be  cultivated,  and  animals  were  domesticated,  we  had  the 
beginning  of  a  fixed  home. 

How  a  community  came  to  be  formed.  —  In  the  early 
days  people  lived  in  large  families 
or  clans.  These  people  had  certain 
tribal  customs  and  the  members  of 
a  given  clan  all  lived  according  to 
these  customs.  Often  they  lived 
in  deadly  enmity  with  people  of 
other  clans  and,  as  in  the  case  of 
our  North  American  Indians,  they 
came  to  hunt  and  live  together  for 
mutual  protection.  In  the  Mid- 
dle Ages  the  people  of  Europe 
built  walled  towns,  often  making 
them  on  the  hilltops  for  protec- 
tion against  their  hostile  neigh- 
bors. So  the  first  communities 
were  formed. 

First  settlements  in  this  coun- 
try.— When  the  early  settlers  came 
to  this  new  world,  they,  too,  were 
exposed  to  unfriendly  inhabitants, 
the  Indians.  But  not  only  did 
they  live  together  for  the  sake  of 
protection,  but  also  for  other  rea- 

A  North  American  Indian.  • 

sons.     Towns  were  settled  because 

of  natural  advantages  which  gave  the  inhabitants  opportu- 
nity for  trade,  water  power,  or  agriculture.  And  the  people 
who  settled  in  these  early  communities  wanted  social  life  as 


FIRST  SETTLEMENTS  IN  THIS  COUNTRY          47 

well.  So  they  had  churches,  schools,  and  public  meeting 
houses.  At  first  life  was  very  simple  and  there  were  few 
trades  or  occupations.  Each  man  was  his  own  carpenter, 
tailor,  and  shoemaker.  But  as  the  settlement  grew  in 
numbers  some  men  who  were  better  carpenters  took  that 
as  their  trade,  while  others  became  tailors  and  still  others, 
shoemakers.  So  gradually,  just  as  life  always  develops, 
the  modern  community  with  its  complex  life  and  its  many 
advantages  has  come  into  existence. 

REFERENCE  BOOKS 

Brigham  and  McFarlane,  Essentials  of  Geography.    American  Book  Company. 

Caldwell  and  Eikenberry,  General  Science.     Ginn  and  Company. 

Cleland,  Geology,  Physical  and  Historical.  (For  teachers.)  American  Book 
Company. 

Clodd,  The  Childhood  of  the  World.    The  Macmillan  Company. 

Dryer,  Physical  Geography.    American  Book  Company. 

Dunn,  The  Community  and  the  Citizen.     D.  C.  Heath  and  Company. 

Gregory-Keller-Bishop,  Physical  and  Commercial  Geography.  (For  teachers.) 
Ginn  and  Company. 

Gilbert  and  Brigham,  Introduction  to  Physical  Geography.  D.  Appleton  and  Com- 
pany. 

Helgard,  Soils,  Their  Formation.     (For  teachers.)     The  Macmillan  Company. 

Hunter,  A  Civic  Biology.     American  Book  Company. 

Hunter,  Laboratory  Problems  in  Civic  Biology.     American  Book  Company. 

Lodge,  Pioneers  of  Science.     The  Macmillan  Company. 

Marten,  The  Ways  of  the  Planets.     Harper  and  Brothers. 

Mitton,  The  Child's  Book  of  Stars.     A.  and  C.  Black,  London. 

Proctor,  Easy  Star  Lessons.     G.  P.  Putnam's  Sons. 

Rogers,  Earth  and  Sky  Every  Child  Should  Know.  Doubleday,  Page  and  Com- 
pany. 

Shaler,  Aspects  of  the  Earth.     (For  teachers.)     Charles  Scribner's  Sons. 

Snyder,  Everyday  Science.     Allyn  and  Bacon. 

Tappan,  Wonders  of  Science.  (Chapters  on  soil  making,  etc.)  Houghton  Mifflin 
Company. 

Tarr,  A  Haniful  of  Soil.  Cornell  University  Nature  Study  Quarterly,  Number 
2,  Oct.  i8go. 

Todd,  New  Astronomy.    American  Book  Company. 


CHAPTER  III 
RESOURCES   OF   THE   COMMUNITY 

Problems.  —  i.  To  find  out  what  our  natural  resources 
are. 

2.  To  learn  the  relation  of  farming  to  a  community. 

3.  To   understand   the   relationship   between   forests   and 
industry. 

4.  To  see  what  forms  of  animal  life  are  valuable  natural 
resources. 

5.  To  learn  something  of  our  mineral  resources. 

6.  To  learn  something  of  coal  and  oil  in  relation  to  com- 
munal life. 

7.  To   learn   about   manufacturing   in  relation   to   com- 
munal life. 

8.  To  iind  out  the  reasons  for  conservation. 

Project  I.  —  A  STUDY  OF  THE  NATURAL  RESOURCES  OF  MY  COM- 
MUNITY. 

a.  To  make  an  inventory  of  the  natural  resources  of  my  com- 
munity. 

b.  To  determine  whether  or  not  these  resources  have  been  util- 
ized by  the  inhabitants  of  "the  community. 

c.  To  find  out  if  resources  are  conserved. 

Natural  resources.  —  Man  in  his  primitive  state  needed 
food,  shelter,  fuel,  and  clothing.  These  primary  needs, 
as  civilization  grew,  were  supplemented  by  many  others. 
Indians  who  inhabited  wooded  territory  had  all  the  wood 
they  needed,  and  if  this  became  exhausted  they  moved  to 

48 


NATURAL  RESOURCES 


49 


Sheep  raising,  fishing,  lumbering,  and  mining  are  among  the  industries  which  depend 
upon  our  natural  resources. 

a  new  supply.  Now  great  manufactories  have  come  into 
existence,  particularly  where  there  is  an  abundance  of 
different  fuels,  — wood,  hard  and  soft  coal,  oil,  and  natural 

H.  W.  CIV.  SCI.  COMM.   —  4 


50  RESOURCES  OF  THE  COMMUNITY 

gas.  From  these  fuels  they  obtain  coke  and  gas,  and  may 
produce  electricity.  These  fuels,  together  with  water 
power,  may  be  used  to  operate  engines  and  yield  mechan- 
ical energy  to  run  various  machines  and  enable  a  com- 
munity to  enter  into  very  many  different  kinds  of  manu- 
facturing. The  raw  materials  near  at  hand  are  likely 
to  determine  the  kind  of  goods  manufactured  in  a  com- 
munity. 

An  inventory  of  our  natural  resources.  —  Since  our 
communities  are  so  dependent  upon  these  resources  it 
will  be  well  for  us  to  make  an  inventory  of  them  and  thus 
we  can  appreciate  why  the  United  States  has  become  such 
a  wealthy  nation  We  have  the  fertile  plains  of  the  Middle 
West,  great  forests  which  are  untouched  in  the  Northwest 
and  in  parts  of  our  northern  states ;  cotton,  cane,  citrus 
fruit  and  truck  farms  in  the  southern  states,  and  the 
vineyards  and  orchards  of  New  York  and  California.  All 
of  these  indicate  a  richness  and  fertility  of  land.  A  visit 
to  the  farms  in  the  central  West  shows  us  that  different 
localities  create  different  kinds  of  wealth:  pigs  in  Iowa, 
cattle  in  Texas  and  the  central  West,  sheep  in  the  moun- 
tain states,  the  great  slaughtering  and  packing  industries 
in  St.  Louis,  Chicago,  and  Omaha.  Then  we  have  the  iron 
mines  of  Minnesota,  the  copper  of  Michigan,  the  gold 
of  the  mountain  states  and  Alaska,  the  coal  of  Pennsyl- 
vania and  Illinois,  the  oil  fields  of  West  Virginia,  Okla- 
homa, and  California,  all  testifying  to  the  richness  of 
our  natural  resources.  Although  the  United  States  has 
only  6  per  cent  of  the  world's  population,  and  only  7 
per  cent  of  the  land  of  the  globe,  yet  we  produce  a  large 
part  of  the  world's  supplies  as  shown  by  the  following 
table: 


FARMING 


THE  UNITED  STATES  PRODUCES  OF  THE  WORLD'S  SUPPLY: 


Aluminum 

60% 

Corn 

75% 

Iron  and  Steel 

40% 

Automobiles 

85% 

Cotton 

60% 

Lead 

40% 

Coal 

52% 

Gold 

20% 

Silver 

40% 

Copper 

60% 

Oil 

66% 

Wheat 

25% 

Richness  of  soil  a  natural  resource.  —  Those  of  us  who 
have  traveled  through  some  of  the  fertile  lands  along 
river  valleys  in  the  Northwest  know  how  lavish  nature 
has  been.  This  country 
has  hardly  begun  to  use 
fertilizers  to  help  enrich  the 
soils  as  Europe  has.  Our 
wheat  crop  was  almost  one 
billion  bushels  in  1919  and 
our  corn  crop  even  more. 

T->  ,1  .   i  i  t 

But     the    yield    per    acre    OI 


The  leading  corn-producing  states.    The 


numbers  represent  a  hundred  million 
bushels  produced  yearly. 

these  and  other  cereal  crops 

is  not  nearly  as  high  as  that  of  Europe  where  the  wornout 
land  is  cultivated  more  carefully  and  constantly  enriched 
with  artificial  fertilizers. 

Farming.  —  The  foundation  of  the  wealth  of  this  coun- 
try is  the  soil.  The  average  production  of  all  crops  for 
five  years  prior  to  1915  was  over  six  billion  dollars  a  year. 
This  is  two  or  three  times  as  great  as  the  money  obtained 
from  any  other  kind  of  industry.  We  find  corn  our  great- 
est crop,  exceeding  one  billion  bushels  a  year.  About 
half  of  the  corn  is  raised  in  the  states  of  Illinois,  Iowa, 
Kansas,  Indiana,  Ohio,  Nebraska,  and  Missouri.  Al- 
though much  corn  is  used  as  food  for  man,  yet  the  bulk 
of  our  corn  crop  is  fed  to  hogs  and  cattle.  We  export  our 
corn  "  on  the  hoof,"  in  the  form  of  pork  and  beef. 


52  RESOURCES  OF  THE   COMMUNITY 

Wheat,  which  has  become  a  crop  of  nearly  a  billion 
bushels  a  year,  is  grown  most  largely  in  Kansas,  Nebraska, 
and  the  Dakotas  and  Minnesota,  with  a  belt  along  the 
Pacific  coast  centering  in  Washington  and  Oregon.  It  is 
a  northern  crop,  and  thanks  to  the  experiments  made  by 
the  Department  of  Agriculture,  we  are  increasing  our  yield 
and  getting  wheats  which  are  more  resistant  to  cold  and 
plant  enemies.  Other  cereal  crops,  —  oats,  rice,  barley, 


Picking  strawberries  for  the  market. 

buckwheat,  and  particularly  forage  crops,  such  as  grass 
and  clover,  are  of  very  great  importance  to  our  central 
and  western  farms.  A  comparatively  new  type  of  farm 
which  is  becoming  very  important  in  the  South  is  the 
truck  farm.  Vegetables  can  be  shipped  by  rail  or  water  so 
that  we  can  get  them  fresh  any  time  of  the  year.  We  also 
find  vegetable  canning,  which  was  first  practiced  in  1846,  be- 
coming a  very  important  adjunct  to  the  work  of  the  farmer. 
Types  of  farming  communities.  —  Since  most  farms 
are  of  large  size,  some  having  several  hundred  acres,  the 


INDUSTRIES  WHICH  GROW  OUT  OF  FARMING     53 

houses  are  scattered.  Machinery  does  much  of  the  work 
and  each  large  farm  is  often  the  center  of  more  than  one 
family.  Farming  communities  are  well-to-do.  The  farmers 
have  their  own  automobiles,  and  the  villages  are  often  set- 
tled by  retired  farmers.  Stores  keep  commodities  which 
are  needed  for  tilling  and  reaping,  also  those  staple  foods 
which  cannot  be  grown  on  the  farm.  Doctors  and  dentists 
and  other  professional  men  locate  in  these  communities. 
There  are  good  churches  and  schools  and  movies  and  the 
post  office  provides  rural  delivery.  There  are  no  very  poor 
nor  very  wealthy  people,  thus  a  farming  community  in 
many  respects  is  ideal. 

Industries  which  grow  out  of  farming.  —  Perhaps. the 
most  important  industry  is  that  of  milling.  As  late  as 
1823  a  small  government  milling  plant  was  established 


A  grain  elevator. 


in  Minneapolis;  to-day  the  Minnesota  mills  supply  hun- 
dreds of  thousands  of  barrels  a  year.  The  flour,  which  was 
once  of  a  poor  quality,  is  now,  because  of  the  introduc- 


54  RESOURCES  OF  THE  COMMUNITY 

tion  of  chilled  iron  and  porcelain  rollers  in  place  of  mill- 
stones, of  a  very  high  grade.  Milling  centers  are  usually 
near  sources  of  water  power  and  must  not  only  be  near  the 
wheat  fields  but  also  on  lines  of  railroad  or  other  trans- 
portation. Much  grain  is  shipped  long  distances  by  boat. 
Great  grain  elevators  have  been  built  in  many  terminal 
places  such  as  Duluth  and  Buffalo. 

The  transportation  of  fruits  and  vegetables  has  already 
been  spoken  of,  as  well  as  the  canning  industry.  The 
sugar  crop  is  of  much  importance,  sugar  cane  being 
grown  in  the  South  and  sugar  beets  in  the  North.  Po- 
tatoes are  also  an  important  crop,  which,  thanks  to  Luther 
Burbank,  have  been  greatly  improved.  Nevertheless, 
Europe  obtains  many  more  bushels  per  acre  than  we, 
because  of  superior  methods  of  cultivation. 

Forest  industries  and  their  communities.  —  Ever  since 
early  colonial  days  forests  have  played  an  important  part. 
Then  they  were  looked  upon  as  a  hindrance  because  they 
covered  the  land  which  the  colonists  wished  to  use  for 
cultivation.  Now,  however,  they  have  become  a  source 
of  many  kinds  of  great  enterprises.  Over  six  hundred 
million  dollars'  worth  of  sawed  lumber  is  produced  every 
year.  Eight  hundred  thousand  wage  earners  are  engaged 
in  lumbering  and  allied  industries,  such  as  the  planing 
mill,  which  makes  interior  woodwork  for  houses,  the  manu- 
facture of  furniture,  and  the  paper  pulp  industry.  Grand 
Rapids,  Michigan,  is  almost  entirely  given  over  to  the  mak- 
ing of  furniture ;  Chicago,  Philadelphia,  and  St.  Louis  also 
manufacture  a  great  deal.  Paper  making  machinery  was  in- 
troduced in  1820  when  paper  was  made  out  of  cotton  or  linen 
scraps.  When  wood  pulp  was  first  used  in  1867  an  immense 
industry  came  into  existence.  At  the  present  time  over  three 


FISHERIES  AND   FISHING   COMMUNITIES 


55 


hundred  million  dollars'  worth  of  paper  is  produced  yearly. 
New  York,  Massachusetts,  Maine,  and  Wisconsin  are 
the  states  most  prominently  interested  in  paper  making. 


"  Logging,"  the  start  of  much  fine  lumber. 

Fisheries  and  fishing  communities.  —  As  early  as  1731 
Massachusetts  had  six  hundred  vessels  and  six  thousand 
hardy  men  engaged  in  fishing.  At  every  available  harbor 
along  the  New  England  coast  small  fishing  communities 
have  sprung  up.  These  are  usually  beautifully  located. 
And  from  the  modest  wooden  houses  the  mothers  and 
sisters  used  to  watch  for  the  return  of  their  loved  ones 
when  the  fishing  fleet  came  in.  The  fishing  industry,  how- 
ever, has  spread  from  New  England  along  the  southern 
coast  as  well  as  to  the  far  West.  The  most  important 
fish  caught  are  the  cod,  mackerel,  herring,  halibut,  and 


RESOURCES  OF  THE   COMMUNITY 


salmon,  while  lobsters,  oysters,  and  clams  are  important 
shore  industries.  As  a  result  of  the  fisheries  there  have 
grown  important  fish-drying  and  fish-canning  establish- 
ments. Gloucester,  Massachusetts,  is  an  example  of  a 
town  largely  given  over  to  this  industry. 

Wild  life  as  a  natural  resource.  —  In  the  early  colonial 
days  birds  and  other  wild  animals  took  a  much  more  im- 
portant place  in  the  life  of  people  than  they  do  to-day. 


Drying  fish  on  the  flakes  in  Gloucester. 

The  Indians  traded  valuable  skins  for  goods  which  the 
colonists  possessed.  At  the  present  time  the  fur  trade  is  of 
great  importance  in  Alaska.  The  fur  seals,  which  have  been 
protected  by  our  Government,  produce  annually  a  greater 
value  in  fur  than  we  paid  to  Russia  for  the  whole  of 
Alaska.  Animals  were  used  for  food.  The  buffaloes  of 
the  plains  were  once  so  numerous  that  the  early  pioneers, 


PROTECTION  OF  BIRDS  57 

after  killing  them,  cut  out  the  tongue  and  left  the  rest  of 
the  carcass  to  rot.  To-day  the  buffalo  is  almost  extinct 
except  for  a  few  privately  owned  herds. 

Destruction  of  birds.  —  Wild  birds,  especially  the  larger 
ones,  must  have  furnished  a  goodly  part  of  the  diet  of  the 
early  colonists.  To-day  the  wild  life  of  the  forest  and 
plain  is  but  a  fraction  of  what  it  once  was.  At  the  time  when 
the  Ohio  Valley  was  first  settled,  the  passenger  pigeons 
flew  over  the  country  in  such  large  flocks  that  they  darkened 
the  sun.  It  is  estimated  that  there  were  over  2,000,000,000 
birds  in  a  single  flock.  To-day,  owing  to  the  indiscriminate 
slaughter  of  these  birds  by  hunters,  there  is  not  a  single 
living  passenger  pigeon  in  existence. 

Value  of  birds.  —  Wild  birds  are  a  great  asset  to  any 
community.  Not  only  are  they  attractive  in  form  and 
color,  but  their  songs  are  learned  so  that  they  are  recog- 
nized by  any  country-bred  girl  and  boy.  More  than  this, 
they  are  of  very  great  importance  to  the  farmer.  A  careful 
study  of  the  diagrams  on  page  58  shows  that  the  food 
of  most  birds  consists  to  a  large  extent  either  of  insects 
injurious  to  vegetation,  or  weed  seeds.  Even  the  despised 
crow  and  robin  make  up  for  their  meals  at  our  expense  by 
eating  harmful  insects,  and  most  of  their  food  consists  of 
wild  fruits.  Many  people  think  that  hawks  are  injurious 
because  the  chicken  hawk  feeds  on  our  barnyard  chicks. 
But  three-fourths  of  all  hawks  are  useful  since  they  feed 
upon  mice  or  other  rodents  which  are  harmful  to  crops. 
Birds  are  an  asset  to  be  carefully  conserved  in  any  com- 
munity. 

Protection  of  birds.  —  Since  birds  do  little  harm  and 
much  good  they  should  be  protected.  Cats  are  probably 
their  greatest  enemy  in  this  country.  It  has  been  esti- 


RESOURCES  OF  THE   COMMUNITY 


English  Sparrow 

C&w  Blackbird— 

CccLbircL- — - 

Brown.  Thrasher  - 
Oro-w 


mated  that  cats  annually  destroy  3,500,000  birds  in  New 
York  State  alone,  and  in  the  United  States  east  of  the 

Mississippi  from 
75,000,000  to  100,- 
000,000  birds, 
mostly  young  ones, 
each  year.  When 
we  add  to  this,  de- 
struction by  hunt- 
ers, small  boys, 
and  certain  birds, 
like  the  English 
sparrow  and  the 
sharp  shinned  hawk, 
we  can  see  the  need 
of  conservation  of 
this  valuable  re- 
source. 

Our  mineral  re- 
sources. The 
yearly  mineral  prod- 
ucts of  this  country 
are  over  two  billion 
dollars.  Of  these 
minerals,  coal  and 
iron  occupy  the 
most  important 
place.  Over  six 

Which  birds  found  in  your  locality  are  helpful  ?         hundred  million  dol- 
Which  are  harmful  ? 

lars    worth  of  coal 

and  five  hundred  million  dollars'  worth  of  iron  are  mined 
yearly  according  to  the  most  recent  census  reports.     When 


Mt   XI  40*  S/tt   60%  -KX    to*  9CK 


IRON  MINING 


59 


we  add  the  copper,  gold,  silver,  lead,  zinc,  and  cement 
products  we  get  a  total  of  about  a  billion  dollars  more. 

Iron  mining.  — '  In  early  times  the  iron  industry  was 
centered  in  many  small  mines  in  the  East,  each  with  its 
little  smelting  works.  Connecticut  iron  mines  were  worked 


Iron  ore  in  the  Mesaba  Range. 

before  the  War  of  the  Revolution  and  continued  in  opera- 
tion for  over  one  hundred  and  fifty  years.  At  the  time 
of  the  Civil  War  over  half  of  the  iron  produced  in  this 
country  came  from  Pennsylvania  because  both  iron  and 
coal  were  found  there.  But  to-day  four-fifths  of  all  iron 
mined  comes  from  the  great  deposits  of  the  Lake  Superior 
region.  It  is  estimated  that  the  United  States  Steel  Corpo- 
ration controls  about  half  the  available  ore  found  in  this 
country.  Germany's  move  early  in  the  World  War  to  seize 
the  rich  iron  mines  in  northern  France  indicates  the  im- 


6o 


RESOURCES  OF  THE  COMMUNITY 


portance  of  iron.  When  we  learn  that  over  1,350,000  tons 
of  materials  manufactured  from  iron  were  thrown  into  the 
Verdun  area  during  the  war,  we  can  see  what  a  tremendous 
waste  of  iron  and  steel  took  place  during  the  period  of  the 
World  War. 

Mining  communities.  —  The  old  picture  of  a  mining 
camp  is  a  thing  of  the  past.  In  northern  Minnesota  "  on 
the  Range,"  where  are  located  the  most  productive  iron 
mines  in  the  world,  the  towns  are  well  built  and  are  well 


Workable  coal  bed 
Areas  that  may  contain  coal 
ij  Coal  beds  under  heavy  cover 


Map  showing  bituminous  coal  beds. 

planned  by  the  great  corporations  that  own  the  mines. 
Their  schools  are  excellent,  the  housing  conditions  are 
good,  and  both  native  American  and  foreign  born  popu- 
lation have  the  advantages  of  schooling  and  recreation 
not  often  found  in  larger  cities.  The  disadvantage  of 
mining  communities  is  largely  due  to  dirt,  smoke,  and 
poisonous  fumes,  especially  in  the  copper  industry. 

Coal.  —  Anthracite  coal  is  restricted  to  an  area  of  about 
five  hundred  square  miles  in  Pennsylvania.     Bituminous 


COAL  MINING  TOWNS 


61 


coal,  however,  comes  from  different  localities  (see  map  on 
page  60).     The  largest  field  exceeds  five  hundred  miles  in 


In  a  coal  mine. 

length,  extending  from  New  York  to  Alabama.  Most 
bituminous  mines  are  found  in  Pennsylvania,  West  Virginia, 
Illinois,  and  Ohio.  Coal  was  first  used  in  quantity  for 
smelting  iron  and  it  was  not  until  the  development  of 
railroad  and  steamship  transportation  that  it  jumped  to 
its  present  enormous  use  of  a  yearly  output  of  over  five 
hundred  million  dollars. 

Coal  mining  towns.  —  Probably  some  of  the  most  im- 
portant civic  work  to  be  done  is  in  coal  mining  towns. 
Here  housing  conditions  are  often  poor.  There  are  many 
foreigners  with  low  living  standards,  and  Americanization 
work  is  much  needed.  Coal  mining  is  unhealthful  and 
somewhat  dangerous.  Child  labor  was  once  quite  preva- 


62 


RESOURCES  OF  THE  COMMUNITY 


lent  among  the  so-called  "  breaker  boys."  The  towns  are 
usually  dirty  and  grimy,  for  coke  making  and  many  smelt- 
ing industries  are  often  associated  with  the  mining  of 
coal. 

Oil  and  its  relation  to  community  life.  —  Although 
oil  was  well  known  to  the  Seneca  Indians  it  was  not  thought 
to  be  worth  anything  by  the  early  colonists.  It  was  not 

until  1859  that  oil  was 
drilled  for  and  pumped 
from  a  well  near  Titus- 
ville,  Pa.  This  was  the 
beginning  of  the  industry 
which  has  advanced  by 
leaps  and  bounds  until 
to-day  great  corpora- 
tions with  hundreds  of 
millions  of  capital,  thou- 
sands of  wells,  and  tens 
of  thousands  of  miles 
of  pipe  line  are  dis- 
tributing oil  from  the 
wells  by  means  of  these 
lines,  tank  cars,  and 
steamers  to  all  parts  of 
the  civilized  world.  The 
greatest  fields  to-day  are 
in  California,  Oklahoma, 
Pennsylvania,  and  West 

Section  through  a  gas  or  oU  well.  Virginia.        In      most      of 

these   localities    natural 

gas  is  also  obtainable,  which  in  many  cities  supplants 
coal  for  lighting  and  fuel  purposes. 


MANUFACTURING  COMMUNITIES  63 

Oil-producing  communities.  —  Since  the  method  of  oil 
production  requires  constant  drilling  in  new  as  well  as  old 
fields  it  means  a  fluctuating  community  existence.  In  1865, 
Pothole  City  was  one  of  the  largest  post  offices  in  Pennsyl- 
vania. To-day  it  is  nothing  but  a  farm.  In  many  parts 
of  the  country  oil-boom  towns  have  grown  up  almost 
overnight,  and  have  been  as  quickly  abandoned  when 
oil  in  that  locality  gave  out.  It  is  evident  that  com- 
munity life  under  such  conditions  is  not  very  favorable. 

Manufacturing  communities.  —  We  have  not  men- 
tioned cotton,  the  great  fiber  crop,  which  gives  occupation 
to  hundreds  of  thousands,  both  in  the  fields  and  in  the 
factories  where  cotton  cloth  is  manufactured.  It  is  in- 
teresting to  know  that  there  are  many  cotton  mills  in 
Massachusetts  far  from  the  source  of  supply.  There 
are  the  great  steel  industries  with  a  production  of  over 
one  billion  dollars'  worth  yearly,  the  foundry  and  machine 
shop  productions  with  a  billion  more;  men's,  women's, 
and  children's  clothing  with  almost  as  great  a  production ; 
the  automobile  industry  with  five  hundred  million  dollars' 
yearly  production,  and  the  hundred  and  one  other  manu- 
facturing industries  which  this  great  country  of  ours  con- 
tains. All  of  these  industries  take  our  natural  resources 
and  turn  them  over  into  manufactured  products  which 
represent  the  wealth  of  the  communities,  hence  't  is  that 
in  our  great  manufacturing  centers  we  find  wealth  in  its 
most  lavish  form.  In  large  industrial  centers  are  our 
finest  museums  and  philanthropic  institutions.  Here  we 
find  our  best  school  systems.  Here  civic  development  is 
worked  out  at  its  best,  but  here  also  we  find,  due  to  the 
high  rents,  high  cost  of  land,  much  congestion,  overcrowd- 
.  ing,  and  poverty. 


64  RESOURCES  OF  THE  COMMUNITY 

Wastefulness  in  the  use  of  our  resources.  —  When  we 
see  the  wealth  of  a  great  city  we  are  prompted  to  ask, 
"Where  does  it  all  come  from?"  We  must  remember 
that,  in  spite  of  man's  ingenuity  and  progress,  wealth  de- 
pends in  the  long  run  upon  the  natural  resources  of  the 
country.  We  are  like  a  man  who  has  a  sum  of  money  in 
the  bank  the  interest  of  which  is  supposed  to  take  him 
through  life.  He  spends  part  of  his  capital  and  in  doing 
this  makes  his  income  less  At  the  present  time  we  are 
spending  our  capital  in  this  country;  especially  of  our 
forests,  our  coal,  and  our  oil  supplies. 

Conservation.  — Theodore  Roosevelt  wisely  preached  con- 
servation, and  showed  his  interest  by  appointing  able  men 
to  put  its  principles  into  practice.  Our  forests,  that  great 
asset  of  ours,  once  covered  the  greater  part  of  the  country 
with  the  exception  of  the  plains  west  of  the  Mississippi 
valley.  To-day,  with  our  life  as  a  nation  just  beginning, 
we  have  used  up  most  of  the  best  wood,  and  have  less  than 
half  of  the  salable  timber  remaining.  Fortunately,  we 
are  making  forest  reservations  where  timber  can  be  taken 
only  under  proper  supervision,  and  we  are  also  replanting 
forest  areas,  thanks  to  the  work  of  the  Bureau  of  Forestry. 

Conservation  of  coal  is  necessary.  In  many  industries, 
we  may  substitute  oil,  water  power,  or  electricity,  but 
we  probably  could  hardly  get  along  without  the  by-prod- 
ucts which  come  from  coke  and  gas  making.  We  use  more 
than  five  tons  of  coal  per  person  a  year.  We  have  waste 
in  imperfect  combustion,  in  the  process  of  coke  making, 
and  most  of  all  at  the  mines.  It  has  been  estimated  that 
for  every  ton  of  coal  mined  almost  half  a  ton  is  wasted  at 
the  mine.  All  these  wastes,  however,  are  now  being  looked 
after  much  more  carefully  than  in  the  past,  for  we  realize 


SCORING  OUR  NATURAL  RESOURCES  65 

that  after  this  coal  is  gone  we  cannot  obtain  any  more. 
Even  greater  waste  is  seen  in  the  use  of  oil  and  natural  gas. 
Carelessness  in  storage  and  in  pumping  is  responsible  for 
enormous  waste,  and  since  natural  gas  is  cheap,  it  is  also 
wasted  both  in  homes  and  by  cities.  We  find  that  oil  or 
petroleum  products  are  being  substituted  for  coal,  but  this 
practice  is  unwise  since  at  the  present  rate  of  production, 
natural  gas  and  oil  will  last  but  about  20  years,  while  we 
have  a  6000  years'  supply  of  coal. 

Conservation  of  our  fish  is  being  taken  care  of  by 
the  United  States  Bureau  of  Fisheries.  Millions  of  fish 
eggs  are  hatched  artificially  each  year  and  placed  in  our 
rivers  and  in  the  ocean.  Laws  are  made  with  respect  to 
the  taking  of  fish  in  the  season  when  they  lay  their  eggs, 
and  other  methods  of  conservation  are  constantly  being 
introduced.  The  Department  of  Agriculture  through  its 
Bureau  of  Animal  Industry  is  watching  our  cattle,  horses, 
sheep,  and  swine,  making  suggestions  for  improvement  and 
aiding  in  production.  The  Department  of  Agriculture  also  has 
hundreds  of  experts  working  to  increase  the  yield  of  crops, 
while  the  Government  through  methods  of  irrigation  is  throw- 
ing open  new  land  constantly  for  the  purpose  of  production. 

Scoring  our  natural  resources.  —  The  score  card  which 
follows  is  intended  to  show  in  a  general  way  the  natural 
resources  of  your  community.  In  scoring  do  not  try 
to  pick  from  all  of  the  headings.  Remember  that  your 
community,  like  all  others,  has  probably  two  or  three 
groups  of  natural  advantages  around  which  the  life  of  the 
community  centers.  These  may  be  agricultural,  grazing, 
forestry,  coal  or  oil,  mineral  wealth,  or  water  power.  Rarely 
do  several  go  together.  Therefore  select  with  care  from 
the  different  groups. 

H.  W.  CIV.  SCI.  COMM.   —  C 


66 


RESOURCES  OF  THE  COMMUNITY 


SCORE  CARD.    NATURAL  RESOURCES  OF  MY  COMMUNITY 

Select  five  of  the  groups  in  the  table  below  in  which  your  community  ranks  the  highest 
and  score  them.    Omit  the  other  five. 


PER- 
FECT 
SCORE 

MY 

SCORE 

Land  producing  excellent  cereal  crops  (20),  moderate 
(10),  poor  (5) 

20 

Land  adapted  for  and  used  for  market  gardening  — 
excellent  (20),  moderate  (10),  poor  (5) 

20 

Land  adapted  for  and  used  to  grow  fruits  and  vege- 
tables in  quantity  giving  rise  to  packing  or  cannery 
industry  (20),  local  consumption  (10) 

20 

Land  covered  with  forests  giving  rise  to  industry  on 
which  community  depends  (20),  forests  for  fuel 
only  (5),  no  forests  (o) 

2O 

Land  suitable  for  grazing:  horses,  cattle,  sheep  or 
swine  raising  on  large  scale  (20),  locally  used  only 

do) 

2O 

Presence  of  natural  waterways  (and  good  harbors, 
giving  cheap  transportation  20),  one  of  above 
(10),  none  (o) 

20 

Presence  of  fish  in  sufficient  numbers  to  give  rise  to 
extensive  industry  (20),  local  markets  (5),  home 
consumption  (2) 

20 

Presence  of  coal  as  leading  industry  of  the  community 
(20),  coal  near  enough  to  be  cheap  and  plentiful 
for  manufacturing  and  homes  (10) 

20 

Natural  gas  and  oil  abundant,  oil  fields  close,  fuel 
cheap  (20),  gas  and  oil  centers  within  about  100 
miles  making  them  cheap  (10) 

2O 

Sources,  of  minerals  make  chief  activity  of  commu- 
nity (20),  minerals  not  present  but  used  in  many 
community  enterprises  (10) 

2O 

TOTAL 

IOO 

REFERENCE  BOOKS 

Bassett,  The  Story  of  Glass.    Penn  Publishing  Company. 
Bassett,  The  Story  of  Leather.    Penn  Publishing  Company. 
Bassett,  The  Story  of  Lumber.    Penn  Publishing  Company. 
Bassett,  The  Story  of  Porcelain.    Penn  Publishing  Company. 
Bassett,  The  Story  of  Silk.    Penn  Publishing  Company. 
Bassett,  The  Story  of  Sugar.    Penn  Publishing  Company. 
Bassett,  The  Story  of  Wool.     Penn  Publishing  Company. 
Bishop  and  Keller,  Industry  and  Trade.     Ginn  and  Company. 


SCORING  OUR  NATURAL  RESOURCES  67 

Brigham  and  McFarlane,  Essentials  of  Geography,  Book  II.  American  Book  Com- 
pany. 

Browne,  Peeps  at  Industries.    Rubber.    A.  and  C.  Black. 

Browne,  Peeps  at  Industries.    Sugar.    A.  and  C.  Black. 

Browne,  Peeps  at  Industries.     Tea.    A.  and  C.  Black. 

Cleland,  Geology,  Physical  and  Historical.    (For  teachers.)  American  Book  Company. 

Dyer,  High  School  Geography.    American  Book  Company. 

Fisher,  Resources  and  Industries  of  the  United  States.    Ginn  and  Company. 

Gowin  and  Wheatly,  Occupations.     Ginn  and  Company. 

Gregory- Keller-Bishop,  Physical  and  Commercial  Geography.     Ginn  and  Company. 

Hunter,  A  Civic  Biology.     American  Book  Company. 

Kissell,  Yarn  and  Cloth  Making.     (For  teachers.)     The  Macmillan  Company. 

Rolt- Wheeler,  The  Boy  with  the  United  States  Foresters.  Lothrop,  Lee,  and  Shepard 
Company. 

Rolt-Wheeler,  The  Boy  ivith  the  United  States  Fisheries.  Lothrop,  Lee,  and  Shepard 
Company. 

Rolt-Wheeler,  The  Boy  with  the  United  States  Survey.  Lothrop, -Lee,  and  Shepard 
Company. 

Samuels,  The  Story  of  Iron.     Penn  Publishing  Company. 

Werther,  How  Man  Makes  Markets.     The  Macmillan  Company. 

Ziegler  and  Jaquette,  Our  Community.    J.  C.  Winston  Company. 


PART  II.  WEATHER  AND  CLIMATIC 
CONDITIONS 

CHAPTER  IV 

THE  EFFECT   OF   CLIMATE   ON   COM- 
MUNITY LIFE 

Problems.  —  i.    To  learn  the  causes  of  the  seasons. 

2.  To  learn  the  relation  of  temperature,  rainfall,  heat,  and 
cold  to  communal  life. 

3.  To  learn  how  health  is  influenced  by  climate. 

Experiments.  —  i.   To  show  the  relation  of  sunlight  to  plant  growth. 

2.  To  show  the  relation  of  temperature  to  plant  growth. 

3.  To  show  the  relation  of  water  supply  to  plant  growth. 

Project.  —  To  FIND  HOW  NEAR  THE  CLIMATE  OF  MY  COMMUNITY 

APPROACHES  THE  IDEAL. 

Make  a  list  of  elements  essential  to  an  ideal  climate.  Grade 
these  elements  in  your  community  climate  according  to  some  stand- 
ard scale  you  have  prepared. 

Climate  and  civilization.  —  In  one  of  the  most  interesting 
scientific  books  that  has  recently  been  written,  Professor 
Ellsworth  Huntington  points  out  that  civilization  and 
progress  go  hand  in  hand  with  a  favorable  climate.  The 
effects  of  differences  in  seasons  as  well  as  moist  and  dry 
atmospheres  all  play  an  important  part  in  acting  upon 
living  things  that  come  under  their  influence.  It  will  be 
the  purpose  of  this  chapter  to  show  some  ways  in  which 
climate  may  affect  the  life  of  our  community. 

68 


THE  SEASONS  AND  HOW  THEY  ARE  CAUSED     69 


Mir  A(/f.  un  tcr.   MX  ate.  JUT.  fa.  MM.  **. 


Early  settlers  and  climate. — We  are  told  that  the  first  Pil- 
grim settlers  were  much  disappointed  at  the  severity  of  the 
New  England  climate.  Although  it  was  fully  one  hundred 
miles  south  of  the  latitude  of  England,  yet  the  winters  were 
much  more  severe,  and  the  summers  hotter.  These  condi- 
tions are  even  more  extreme  in  those  parts  of  the  United 
States  that  lie  farther  inland  on  the  same  parallel  of  lati- 
tude. The  early  set- 
tlers did  not  realize 
that  England  and  the 
whole  coast  of  north- 
ern Europe  owed  its 
mild  climate  to  the 
westerly  winds  com- 
ing from  the  ocean. 
They  doubtless  owed 
their  sturdy  growth 
and  endurance,  in 
part  at  least,  to  the 
great  changes  in  the 
climate  to  which  they 
were  exposed. 

The  seasons  and 
how  they  are  caused. 
—  The  working  out 
of  the  discoveries  of  Copernicus,  Galileo,  and  Newton 
has  given  scientists  the  basis  on  which  they  have  established 
most  of  our  knowledge  about  the  action  of  our  earth  in 
space.  We  remember,  of  course,  that  the  earth  revolves 
around  the  sun,  making  a  complete  circuit  once  in  about 
365  days,  and  we  surely  know  that  as  the  earth  goes 
spinning  through  space,  it  rotates  once  on  its  own  axis  in 


90 


70 


The  top  chart  shows  average  hours  per  day  of  sun- 
shine, clouds,  and  darkness  for  each  month  in 
1910  in  New  York. 

The  lower  chart  shows  the  industrial  accidents  in 
three  successive  years.  Notice  that  in  general,  on 
days  with  least  sunshine,  there  are  the  greatest 
number  of  accidents. 


yo      EFFECT  OF  CLIMATE  ON  COMMUNITY  LIFE 


24  hours.  But  we  are  apt  to  forget  that  the  place  of 
the  earth,  the  revolution  of  the  moon  about  the  earth,  the 
tides,  and  many  other  phenomena  are  due  to  the  important 
force  of  gravitation. 

If  we  think  back  to  our  geography,  we  shall  remember  that 
as  the  earth  revolves  around  the  sun  its  axis  is  inclined 
towards  the  plane  of  the  earth's  orbit.  Thus  the  sun's  rays 
strike  the  earth's  surface  at  more  of 
an  angle  at  certain  times  than  at 
others.  If  you  hold  a  piece  of 
perforated  cardboard  about  one  foot 
from  the  floor,  and  parallel  to  it, 
early  in  the  morning,  so  that  the 
sun's  rays  will  pass  through  the 
hole,  and  then  compare  the  area  of 
sunshine  on  the  floor  with  the  area 
formed  at  noon  by  holding  the 
card  in  the  same  position,  you  will 
note  a  considerable  difference.  The 
rays  meet  the  surface  of  the  earth 
more  nearly  at  right  angles  at  noon, 
hence  they  cover  less  space.  If  the 
earth  receives  the  sun's  rays  at  a 
greater  angle,  they  are  spread  over 
a  greater  surface  and  we  receive  less 
heat  on  a  given  surface.  The  sea- 
sons, also,  depend  upon  the  angle  at  which  the  sun's  rays 
strike  the  earth.  If  we  look  at  the  diagram,  we  notice  that 
in  a  similar  manner  the  heat  of  the  torrid  zone  and  the 
lack  of  heat  at  the  poles  of  the  earth  are  due  to  this  same 
fact.  The  sun  is  north  of  the  equator  in  summer  and  south 
of  it  in  winter.  Can  you  explain  why  this  should  give  us 


The  cause  of  our  seasons 
explained. 


SUNLIGHT  — A  FACTOR  IN  CLIMATE 


7.1 


a  hot  season  in  the  one  case  and  a  cold  one  in  the  other  ? 
It  is  an  interesting  fact  that  in  winter  we  are  about  three 
million  miles  nearer  the  sun  than  in  summer,  and  yet  the 
slanting  rays  make  it  colder. 

Sunlight — a  factor  in  climate.  —  We  have  already  learned 
that  sunlight  is  a  very  important  factor  in  and  about 
our  homes.  Sunlight  in  moderation  makes  our  crops  grow. 


MEAN   ANNUAL  SUNSHINE  IN  THE   UNITED  STATES 


It  gives  necessary  warmth  to  the  soil,  so  that  the  longer 
day  in  summer  with  its  vertical  rays  of  sunlight  warms 
the  earth,  rendering  it  favorable  for  the  growth  of  crops. 
Evidence  of  the  value  of  sunlight  for  plants  is  easily  secured 
in  the  following  experiment. 

Experiment.  —  To  show  the  relation  of  sunlight  to  plant  growth. 

Materials:  Two  beans. 

Method:    Plant  the  beans  where  they  have  the  same  temperature  and 

moisture,  but  in  one  case  in  darkness  and  in  the  other  case  in  the  light. 

Notice  the  appearance  of  the  sprouts  after  a  number  of  days. 
Conclusion:  What  does  sunlight  do  to  the  bean  plant? 


72       EFFECT  OF   CLIMATE  ON   COMMUNITY  LIFE 

Sunlight  determines,  very  largely,  the  temperature,  and 
so  has  another  indirect  influence  upon  the  growth  of 
plants.  Just  how  this  influence  affects  plant  growth  may 
also  be  shown  by  an  experiment. 

Experiment.  —  To  show  the  effect  of  temperature  on  plant  growth. 
Materials:  Three  cups.    Sawdust.     Pieces  of  cardboard  to  cover  cups. 

Beans  or  peas. 

Method:  Soak  the  beans  or  peas  overnight.  Place  an  equal  number 
in  each  of  three  cups.  Cover  cups  with  cardboard  so  as  to  exclude 
light.  Place  one  cup  in  ice  box;  one  cup  in  living  room;  one  cup 
near  kitchen  stove.  Add  just  enough  water  daily  to  keep  sawdust 
slightly  moistened.  At  the  end  of  five  and  ten  days  record  your 
findings. 
Conclusion  :  What  effect  does  temperature  have  on  plant  growth? 

Daylight  saving.  —  One  result  which  the  war  has  brought 
about  in  many  communities  is  the  change  of  business  hours 
in  the  summer  months  so  as  to  utilize  the  longer  period  of 
unused  light  which  comes  in  the  morning.  This  also  gives 
the  workers  a  longer  evening  for  recreation.  The  plan  has 
much  in  its  favor  although  it  has  met  with  some  opposi- 
tion from  farmers  and  others  who  do  not  benefit  by  the 
afternoon  hours.  It  made  a  considerable  saving  in  fuel 
and  light  at  a  time  when  we  needed  coal  most.  A  strong 
argument  for  continuing  daylight  saving  is  that  it  will 
save  much  fuel  in  the  future,  and  it  also  means  a  length- 
ened play  period  to  hundreds  of  thousands  of  workers 
who  otherwise  would  be  deprived  of  this  playtime. 

Changes  in  temperature  in  relation  to  community  life.  — 
Tropical  climates  or  extremely  cold  climates  are  unfavor- 
able in  their  effect  on  mankind.  We  have  already  spoken 
of  this,  and  we  know  that  Northerners  going  into  the  tropics 
soon  lose  their  ambition  and  settle  down  to  a  life  of  short 
hours  of  work.  This  seems  to  be  because  of  the  lack  of 


RAINFALL  A  FACTOR 


73 


stimulation  in  such  a  climate.  In  the  far  north  there 
are  long  periods  of  darkness,  and  the  monotony  brought 
about  by  the  lack  of  temperature  and  light  changes 
causes  an  unfavorable  reaction  on  the  people  living  there. 
The  moderate  changes  which  come  in  a  temperate  climate, 
especially  the  cold  winters  and  warm  summers,  undoubtedly 


180°    160°     140°     120°    100°      80°      60°      40°      20°        0° 


40°      60°      80°     100°    120°    140°     160°    180° 


180°    160°    140°     120°    100°     80°      60°     40°      20°       0°       20°      40°      60°      80°     100°    120°    140°    160°    180° 

The  distribution  of  human  energy  on  the  basis  of  climate.    (After  Huntington.) 

do  much  toward  making  our  people  the  active  and  resource- 
ful race  that  they  are. 

Rainfall  a  factor.  —  We  have  all  seen  that  rain  plays 
a  very  important  part  for  the  inhabitants  of  the  earth. 
Let  us  see  by  a  simple  experiment  the  relation  of  water 
to  plants. 

Experiment.  —  To  show  the  relation  of  water  supply  to  plant  growth. 

Materials:  Two  small  trays  or  boxes.     Sawdust.     Pea  or  bean  seeds. 

Method:  Soak  the  peas  or  beans  overnight  and  plant  in  equal  numbers 
in  each  box.  Cover  with  sawdust.  The  sawdust  in  one  box  is  kept 
well  moistened.  Add  no  water  to  the  other.  After  one,  two,  and 
three  weeks  make  drawings  and  report  to  the  class. 

Conclusion:  What  effect  does  water  have  on  plant  growth? 


74       EFFECT  OF   CLIMATE  ON   COMMUNITY  LIFE 


We  see  that  plants  need  water  no  less  than  people  do. 
Rainfall  makes  the  type  of  community.  Farming  depends 
to  a  large  extent  upon  the  amount  of  rain  and  sun.  If 
the  summers  are  hot,  rain  becomes  a  necessity,  both  for 


8IEJJ.R.A  NEVADA 
61.18  In. 
,47.02  in, 


PACIFIC 
OCEAN 


22.77  in. 
18.44  in. 


8AGRAMENTO     VALLEY 

19.78  in.  2.     ^-S11*. 

I 

1 


0  Sea.Level  25  miles    50 


the  protection  of  the  soil  and  for  the  plants  and  seeds  that 
are  in  it.  Rain  also  is  a  necessary  factor  in  the  raising  of 
crops.  In  the  great  Middle  West,  where  the  rainfall  is  from 
twenty  to  thirty  inches  a  year,  wheat  is  the  staple  crop, 
while  in  the  East  and  the  South  there  are  more  diversified 
crops,  due  to  the  fact  that  the  rainfall  is  much  greater,  be- 
ing between  forty  and  seventy  or  more  inches. 

Influence  of  water  upon  climate.  —  It  is  not  uncommon 
for  us  in  the  hot  summer  to  make  visits  to  the  seashore  or 
some  mountain  lake.  Those  of  us  who  have  lived  near 
the  shores  of  the  Great  Lakes  know  that  the  summers  are 
much  cooler  and  the  winters  somewhat  warmer  than  they 
are  in  towns  at  some  distance  from  these  lakes.  Along 
Lake  Michigan  and  Long  Island  Sound  an  evening  breeze 
from  off  the  water  blows  over  the  land,  cooling  and  re- 
freshing those  who  live,  there. 

If  we  think  back  to  the  heating  of  rooms,  we  remember 
that  the  stove  set  up  convection  currents  in  the  room. 
The  same  thing  occurs  on  a  larger  scale  between  land  and 
bodies  of  water.  During  the  day  the  temperature  of  the 
land  rises  higher  than  does  the  temperature  of  the  water 


THE  EFFECT  OF  STORMS  75 

of  the  lake.  The  heated  air  rises  from  the  land,  and  as  it 
does  so,  cooler  and  heavier  air  makes  its  way  in  from  the 
lake  to  take  its  place.  This  accounts  for  a  breeze  and  a 
more  even  temperature  of  the  city  or  town  located  near  a 
body  of  water.  In  the  winter  months  the  lake  or  ocean 
loses  its  heat  more  slowly  than  the  land  and  so  prevents 
extremely  low  temperatures  in  its  vicinity.  Hence  it  is 
no  uncommon  thing  to  find  no  snow  in  New  York  City  and 
along  the  sea  coast  while  it  is  several  inches  deep  less  than 
a  hundred  miles  from  the  coast.  Bodies  of  water  by 
means  of  their  stored  heat  also  have  an  effect  upon  the 
severity  and  the  time  of  killing  frosts. 

The  effect  of  storms.  —  We  have  seen  that  bodies  of 
water  influence  winds.     Such  winds  make  life  bearable  in 


ft 


A  flooded  city,  the  result  of  heavy  rainfall  causing  rivers  to  overflow  their  banks. 

many  tropical  countries,  especially  where  the  trade  winds 
blow  in  from  the  ocean  at  certain  intervals  during  the  day, 
causing  evaporation,  which  is  a  cooling  process.  The 
presence  of  wind  belts  over  ocean  and  land  is  well  known 


76      EFFECT  OF  CLIMATE  ON  COMMUNITY  LIFE 

to  all  those  who  have  studied  geography.  Our  cyclonic 
storms  occur  in  one  of  these  wind  belts.  These  storms, 
while  they  do  damage,  yet  supply  the  needed  rainfall. 
Thus  the  eastern  part  of  our  country  owes  much  of  its 
fertility  to  such  storms.  Prolonged  and  severe  rainfall 
at  times  causes  rivers  to  overflow  their  banks,  doing  much 
damage  to  crops,  to  buildings,  and  to  railroads.  Local 
conditions,  such  as  high  hills,  mountains,  lakes,  or  forests, 
may  also  have  a  great  effect  upon  the  prevailing  winds, 
and  may  do  much  in  making  the  community  a  pleasant 
or  an  undesirable  place  in  which  to  live.  The  occurrence 
of  severe  wind  storms,  such  as  tornadoes  with  accompany- 
ing hail,  is  sometimes  very  destructive  to  crops. 

The  railroad  industry  is  greatly  affected  by  cold  and 
snowfall.  The  snow  blockades  on  the  railroads  of  the 
northern  part  of  the  country  have  led  to  the  construction 
of  huge  snow  tunnels  and  wind  breaks,  and  to  the  inven- 
tion of  the  rotary  snow  plow.  The  freezing  of  harbors 
in  the  same  way  influences  the  commercial  importance  of 
a  city,  while  on  the  other  hand  harbors  which  are  located 
in  regions  where  the  trade  winds  blow  constantly  are  much 
favored.  Duluth,  Vladivostok,  Petrograd,  and  the  north- 
ern ports  of  Germany  are  examples  of  inclosed  ports. 
Canada  is  much  handicapped  by  the  winter  closing  of  the 
St.  Lawrence  River,  while  the  ports  of  New  York,  Liver- 
pool, or  Buenos  Aires  are  examples  of  favored  localities. 

Industry  affected  by  climate.  —  It  goes  without  saying 
that  such  industries  as  farming  or  lumbering  depend  largely 
upon  climate.  Many  manufacturers  as  well,  especially 
those  who  use  the  products  of  the  farm  or  raw  lumber, 
build  their  factories  near  the  source  of  supply.  Others 
who  make  use  of  water  power  are  also  indirectly  dependent 


HEALTH  INFLUENCED  BY  CLIMATE  77 

upon  the  climate.  More  than  this,  workmen  in  factories, 
or  indeed  in  any  occupation,  are  very  greatly  influenced 
by  climate. 

A  recent  study  of  temperature  by  a  committee  on  venti- 
lation in  New  York  State  found  that  15  per  cent  less 
work  was  done  by  a  group  of  people  working  in  a  tem- 
perature of  70  degrees  Fahrenheit  than  when  the  same 
group  worked  in  a  temperature  of  68  degrees  Fahrenheit, 
while  if  the  heat  became  as  high  as  86  degrees  they  did 
37  per  cent  less  work  than  they  did  at  68  degrees. 

Another  authority  on  weather  has  shown  that  one  of  the 
chief  conditions  that  enabled  the  German  nation  to  fight 
for  so  long  against  what  seemed  great  odds  was  the  stimu- 
lating climate,  which  thus  helped  the  people  to  do  more 
work  without  feeling  the  fatigue  that  would  come  to  those 
less  advantageously  located. 

Frequent  changes  of  temperature,  such  as  mark  the 
climate  in  most  of  the  United  States,  are  stimulating,  and 
add  to  the  total  energy  of  the  people. 

Health  influenced  by  climate.  —  An  interesting  study 
has  been  made  by  Huntington  on  what  he  calls  the  climatic 
energy  in  this  country  compared  with  the  death  rate  in 
different  parts  of  the  country.  His  maps  on  climate  en- 
ergy have  been  worked  out  from  a  study  of  the  civilization 
and  achievements  of  people  in  all  parts  of  the  world,  and 
based  on  the  climate  of  that  part  of  the  world  in  which 
they  live.  The  map  for  the  United  States  shows  that  cer- 
tain states  to  the  east  and  north  enjoy  a  somewhat  more 
favorable  climate  than  other  states .  He  shows  also  that  the 
death  rate  in  areas  that  have  the  greatest  climatic  energy 
is  less  than  in  those  states  where  the  climatic  energy  is  not 
so  great.  While  many  factors  probably  enter  into  the 


78       EFFECT  OF   CLIMATE   ON   COMMUNITY  LIFE 

formation  of  these  figures,  yet  we  cannot  escape  the  con- 
clusion that  climate  does  play  a  very  important  part  in  our 
success  or  failure  in  life,  and  in  making  a  community  a 
favorable  place  in  which  to  live.  It  is  also  a  well-known 
fact  that  there  are  more  epidemic  diseases  among  people 
in  tropical  climates  than  in  the  temperate.  This  is  due 
in  part  to  lack  of  sanitary  measures. 

What  is  an  ideal  climate  ?  —  From  all  that  we  have  just 
seen,  we  are  now  ready  to  give  some  sort  of  answer  to  this 
question.  The  most  favorable  climate  must  certainly  not 
be  very  cold  or  very  hot.  It  must  have  some  rainfall,  at 
least  thirty  inches  a  year,  to  be  ideal.  We  should  be  lo- 
cated near  enough  to  large  bodies  of  water  so  that  we 
may  benefit  from  their  moderation  of  temperature  and 
humidity.  On  the  other  hand,  a  high  humidity,  often 
found  along  bodies  of  water  in  summer,  is  uncomfortable. 
Above  all,  our  climate  should  have  a  large  number  of 
sunny  days,  so  that  health  may  be  an  asset  to  our  com- 
munity. 

REFERENCE  BOOKS 

Atmospheric  Phenomena.    General  Science  Quarterly,  Salem,  Mass.    January,  1921. 

Brigham  and  McFarlane,  Essentials  of  Geography,  Book  II.  American  Book 
Company. 

Caldwell  and  Eikenberry,  General  Science.     Ginn  and  Company. 

Cox  and  Arrington,  The  Weather  and  Climate  of  Chicago.  University  of  Chicago 
Press. 

Gilbert  and  Brigham,  Introduction  to  Physical  Geography.  D.  Appleton  and  Com- 
pany. 

Gregory-Keller-Bishop,  Physical  and  Commercial  Geography.  (For  teachers.) 
Ginn  and  Company. 

Harrington,  About  the  Weather.    D.  Appleton  and  Company. 

Houston,  The  Wonder  Book  of  the  Atmosphere.     Stokes  Company. 

Hunter,  A  Civic  Biology.    American  Book  Company. 

Hunter,  Laboratory  Problems  in  Civic  Biology.     American  Book  Company. 

Huntine;ton,  Civilization  and  Climate.     (For  teachers.)     Yale  University  Press. 

Lake,  General  Science.     Silver,  Burdett  and  Company. 


WHAT  IS  AN  IDEAL  CLIMATE?  79 

Rolt-Wheeler,  The  Boy  with  the  United  States  Weather  Men.  Lothrop,  Lee,  and 
Shepard  Company. 

Smith  and  Jewett,  Introduction  to  the  Study  of  Science.  The  Macmillan  Com- 
pany. 

Snyder,  Everyday  Science.     Allyn  and  Bacon. 

Trafton,  Science  of  Home  and  Community.     The  Macmillan  Company. 

Van  Buskirk  and  Smith,  The  Science  of  Everyday  Life.  Houghton  Mifflin  Com- 
pany. 

Ward,  Climate.     (For  teachers.)     G.  P.  Putnam's  Sons. 


CHAPTER  V 

THE  WEATHER  AND  THE  WEATHER 
BUREAU 

Problems.  —  i.  To  learn  about  air  conditions  affecting 
weather. 

2.  To  understand  the  use  of  weather  instruments. 

3.  To  learn  what  is  meant  by  relative  humidity  and  how 
to  measure  it. 

4.  To  understand  the  causes  of  clouds  and  rain. 

5.  To  learn  the  nature  of  local  storms. 

6.  To  learn  the  nature  of  cyclonic  storms. 

7.  To  learn  about  the  work  of  the  weather  bureau. 

Experiments. —  i.   To  make  an  experimental  barometer. 

2.  To  measure  a  height  with  an  aneroid  barometer. 

3.  To  show  the  relation  of  humidity  and  temperature  to  moisture 
capacity. 

4.  To  measure  the  relative  humidity  of  the  air. 

Project  I.  —  To  KEEP  A  WEATHER  RECORD  FOR  six  MONTHS. 
Project  n. — To  MAKE  A  RAIN  GAUGE  AND  TO  KEEP  A  RECORD 

OF   RAINFALL   FOR   SIX  MONTHS. 

A  visit  to  the  weather  bureau.  —  Have  you  ever  visited 
the  weather  bureau  in  any  large  city?  If  so,  you  doubtless 
remember  the  interesting  trip  taken  to  the  top  of  a  tall 
building  where  the  government  officials  work  with  their 
various  recording  instruments.  Here  you  saw  barometers 
and  thermometers,  wind  gauges  and  rain  gauges,  anemom- 
•eters  and  hygrometers.  Doubtless  you  learned  something  of 

80 


THE  THERMOMETER 


8l 


A  thermograph. 


their  uses.  Or  perhaps,  in  your  own  school,  you  have  had 
an  opportunity  to  learn  something  about  them  and  to 
use  them.  Each  boy  and  girl,  although  not  able  to 
understand  and  use  all  of  these  instruments,  yet  should 
be  able  to  read  and  compre- 
hend the  maps  which  are  sent 
out  by  the  United  States 
Weather  Bureau,  and  which 
may  be  obtained  for  the  ask- 
ing for  your  own  school. 
The  life  in  our  community 
is  controlled  to  a  very  great 
extent  by  the  weather  we  have ;  and  the  welfare  of  the 
people,  especially  outside  of  large  cities,  depends,  in  part, 
on  some  knowledge  of  the  weather. 

What  is  weather?  —  We  observe  the  various  changes 
in  the  atmosphere  which  come  to  us  day  by  day.  It  may 
be  clear  or  cloudy,  calm  or  windy,  hot  or  cold,  wet  or  dry. 
We  speak  of  these  daily  changes  as  changes  in  weather, 
and  the  average  weather,  taken  day  by  day,  week  by 
week,  season  by  season,  makes  up  our  climate.  These 
changes  which  occur  in  the  weather  can  be  predicted  with 
a  great  deal  of  accuracy  by  any  one  who  has  made  a  care- 
ful study  of  clouds,  winds,  and  especially  of  air  pressure. 

The  thermometer.  —  We  have  already  learned  something 
of  the  principle  of  the  thermometer,  a  glass  tube  with  a 
bulb  at  one  end  filled  with  mercury  or  some  other  fluid  that 
expands  and  contracts  with  heat  and  cold.  The  tube  is 
sealed  while  hot,  leaving  a  vacuum  above  the  mercury 
when  it  cools.  The  scale  is  then  marked  on  the  glass  tube 
according  to  the  Fahrenheit  or  Centigrade  marking,  the 
Fahrenheit  having  the  freezing  point  of  water  marked 

H.  W.  CIV.  SCI.  COMM.  - — 6 


82   THE  WEATHER  AND  THE  WEATHER  BUREAU 

''32  degrees"  and  the  boiling  point,  "  212  degrees,"  while  the 
Centigrade  has  the  freezing  point  marked  "Zero"  and  boil- 
ing, "  100  degrees."  The  Centigrade  is  used  in  most  scien- 
tific work,  although  the  Fahrenheit  thermometer  is  in  com- 
mon use,  and  is  used  by  the  United  States  Weather  Bureau. 
Useful  thermometers  for  determining  extremes  of  tem- 
perature are  of  the  self -registering  type,  shown  below.  In 
one  type  of  maximum  thermometer,  the  mercury  pushes  a 
movable  index  placed  inside  the  bore  along  ahead  of  it,  and 
upon  contracting,  leaves  the  index  marking  the  point  of 
greatest  expansion.  In  the  minimum  thermometer,  the 


Maximum  and  minimum  thermometers. 

index  is  covered  with  alcohol  in  the  bore  of  the  tube.  When 
the  alcohol  contracts,  the  surface  film  draws  the  index  along, 
but  when  alcohol  expands,  it  moves  by  the  index,  which 
thus  marks  the  lowest  temperature  reached.  It  is  impor- 
tant for  a  study  of  weather  conditions  to  have  a  continu- 
ous record  of  temperature.  Such  a  record  is  produced 
automatically  by  an  instrument  called  the  thermograph. 
Air  pressure  in  its  relation  to  weather.  —  We  have  al- 
ready learned  that  air  has  weight.  Its  pressure  on  us  at  sea 
level  averages  about  14.7  pounds  to  the  square  inch.  We 
sometimes  get  a  little  idea  of  this  pressure  by  being  suddenly 
dropped  down  in  a  rapidly  running  elevator.  The  change  of 
air  pressure  may  be  noticed  in  the  effect  on  the  ears.  The 
instrument  which  measures  the  pressure  of  the  air  is  called 


HOW  THE  BAROMETER  IS  USED 


the  barometer.  A  simple  barometer  is  quite  easy  to  make, 
for  we  can  perform  an  experiment  made  a  great  many  years 
ago  by  Torricelli,  a  pupil  of  Galileo.  He  wished  to  know 
what  the  pressure  of  air  was,  and  constructed  an  instrument 
to  measure  it  in  somewhat  the  same 
way  as  described  in  the  following  ex- 
periment. 

Experiment.  —  To  make  an  experimental  barom- 
eter. 

Materials:  A  stout  glass  tube  33  inches  long,, 
closed  at  one  end.  Mercury.  Small  fun- 
nel. Mercury  trough. 

Method:  Hold  the  glass  tube  inclined  a  little 
from  vertical.  Place  the  funnel  in  the  tube 
and  pour  mercury  in  to  fill  the  tube.  A 
suitable  funnel  may  be  made  by  heating  the 
stem  of  a  thistle  tube  near  the  bulb  and 
drawing  it  out  to  reduce  the  diameter.  Cut 
this  off  at  its  narrowest  point.  Work  the  air 
out  of  the  tube  by  jarring.  When  the  tube 
is  full  of  mercury,  cover  the  open  end  with 

the  finger,  invert,  hold  end  under  mercury  in  the  trough,  and  remove 
the  finger. 

Result  and  Conclusion:  What  happens  when  the  finger  is  removed? 
Hold  the  tube  vertically  and  measure  the  height  of  the  column  of  mer- 
cury in  the  tube  above  the  level  of  mercury  in  the  trough.  What 
holds  it  up?  Read  the  barometer.  Why  does  this  experimental  ba- 
rometer read  lower? 

Air  bubbles  in  the  mercury  of  the  experimental,  barometer  maybe  re- 
moved by  the  use  of  a  fine  wire.  A  barometer  made  in  this  way  has 
some  air  left  in  it  and  so  reads  lower  than  a  standard  barometer.  The 
air  can  be  removed  only  by  boiling  the  mercury  in  the  tube. 

How  the  barometer  is  used.  —  The  height  of  a  column 
of  mercury  under  standard  conditions  is  30  inches  and 
represents  a  pressure  of  14.7  pounds  per  square  inch.  A  rise 
or  fall  of  the  column  indicates  an  increase  or  decrease  in 


Experimental  barometer. 


84   THE  WEATHER  AND  THE  WEATHER  BUREAU 


air  pressure.  The  air  pressure  in  your  own  locality  de- 
pends on  the  altitude  above  sea  level ;  for  example,  Lead- 
ville,  Colorado,  with  an  altitude  of  over  10,000  feet,  shows 
a  height  of  mercury  of  only  20  inches.  The  air  pressure 
decreases  up  to  10,000  feet  at  the  rate  of  approximately 
i  inch  for  each  900  feet.  A  fall  of  i  inch  in  the  barometer 
represents  a  rise  of  910  feet  near  the  earth  and  1500  feet 

3  miles  above  sea  level.  If  you 
lived  at  an  altitude  of  2500  feet 
above  sea  level,  what  would  be 
the  normal  reading  for  your 
barometer  ? 

Aneroid  barometer.  —  The  mer- 
curial barometer  just  described 
cannot  be  carried  about  easily, 
as  it  must  be  kept  in  a  vertical 
position.  The  aneroid  barome- 
ter may  be  carried  about  like  a 
watch  or  clock,  and  thus  is  used 
by  explorers  and  for  practical 
work  in  the  field.  Just  inside  the 
case  of  the  aneroid  barometer 
is  a  small  flat  box  of  thin  cor- 
rugated metal.  From  this  box 
the  air  has  been  removed.  The  walls  are  so  delicate  that  a 
slight  increase  in  pressure  causes  the  walls  to  come  closer  to- 
gether, while  a  decrease  in  pressure  allows  them  to  go  farther 
apart.  This  motion  is  transferred  by  lever  action  to  a 
hand  which  moves  along  a  scale  to  show  the  pressure  of 
the  atmosphere.  The  aneroid  is  used  both  for  weather 
observation  and  to  measure  the  height  of  mountains  or 
the  altitude  of  aircraft. 


Explain  the  working  of  the  aneroid 
barometer  from  this  diagram. 


HUMIDITY 


Experiment.  —  To  measure  a  height  with  an  aneroid  barometer. 

Materials:  An  aneroid  barometer. 

Method:  Study  the  scale  and  learn  how  to  read  fractions  of  a  division. 
Assume  the  relation  of  rise  in  altitude  to  the  decrease  in  pressure  to 
be  910  feet  to  i  inch.    Read  the  barometer  at  the  base  of  a  high  build- 
ing or  better  a  high  hill  or  small 
mountain.     Carry  the  barome- 
ter to  the  top  and  read  again. 
Read  again  at  the  top  and  again 
when   reaching  the   base.     Av- 
erage the  two  results. 

Results  and  Conclusion:  From 
these  figures  what  do  you  con- 
clude the  height  of  the  building 
or  hill  to  be? 


A  barograph. 

The     barograph.         The 

standard  barometer  for  weather  bureau    readings  is  the 
mercurial  barometer.     But  the  aneroid  is  used  in  the  self- 


Barograph  record. 

recording  instrument  called  the  barograph.  A  pen  which 
rises  and  falls  under  changes  of  air  pressure  records  these 
changes  on  sheets  of  paper  attached  to  the  outer  surface 
of  a  revolving  drum,  which  is  operated  by  clockwork. 

Humidity.  —  What  do  we  mean  by  humidity?  We  have 
felt  an  effect  of  it,  for  the  discomfort  of  a  muggy  day  in 
summer  is  familiar.  If  we  place  a  dish  of  water  in  an 
air-tight  box,  the  water  will  evaporate  until  the  inclosed 
space  holds  all  the  water  vapor  it  can.  Then  the  air  is  said 
to  be  saturated,  but  we  really  mean  that  the  space  is  saturated, 


86   THE  WEATHER  AND  THE  WEATHER  BUREAU 

because  there  would  be  the  same  amount  of  moisture  in  the 
space  whether  air  were  present  or  not.  Some  of  the  factors 
which  determine  the  capacity  of  air  (space)  for  holding 
moisture  may  be  found  out  by  this  experiment. 

Experiment.  —  To  show  the  relation  of  humid- 
ity and  temperature  to  moisture  capacity : 
Materials:  Four  i -liter  flasks.  Small  sponge. 
Cheesecloth.     Fused   calcium   chloride. 
Glass  rod.     Stoppers. 

Method  and  Results:  (i)  Prepare  a  flask  of 
moist  air  by  hanging  a  small  wet  sponge 
in  the  flask.  Prepare  a  flask  of  dry  air  by  hanging  a  cheesecloth  bag  of 
fused  calcium  chloride  in  it.  From  a  wet  glass  rod  let  one  drop  of 
water  fall  into  each  flask.  In  which  case  does  it  evaporate  into  the  air 
in  the  shortest  time  ? 

(2)  On  a  cold  day  close  two  dry  flasks  which  have  been  open  in 
the  room  for  several  hours.  Place  one  of  these  out  of  doors  where  the 
temperature  is  20  or  more  degrees  colder  than  indoors.  After  10  min- 
utes, put  a  drop  of  water  in  the  flask  kept  indoors  and  another  drop  in 
the  flask  kept  in  the  cold.  Observe  from  tune  to  time  until  you  have  evi- 
dence to  prove  whether  the  cold  or  the  warm  air  takes  up  the  water  first. 
Conclusion:  What  conclusion  do  you  draw  from  these  experiments? 

We  thus  see  that  when  the  air  is  cooled,  less  water  is 
taken  up  than  if  the  air  is  warm,  and  that  dry  air  has  a 
higher  capacity  for  taking  up  vapor  than  moist  air.  It  is 
possible  to  measure  the  amount  of  water  taken  up  by  the 
air.  This  weight  of  water  which  the  air  or  space  actually 
holds  is  called  the  absolute  humidity,  but  the  humidity 
which  we  see  reported  in  the  daily  papers  is  the  relative 
humidity;  that  is,  the  ratio  between  the  amount  of  water 
that  the  air  contains  and  what  it  would  contain  if  it  were 
saturated.  For"  example,  if  the  humidity  is  60%,  that  means 
that  the  air  contains  60%  of  the  amount  of  water  that  it 
would  contain  at  that  temperature  if  the  air  were  saturated. 

Humidity  in  buildings.  —  Every  one  of  us  knows  how 


HUMIDITY  IN  BUILDINGS 


87 


uncomfortable  a  crowded  auditorium  becomes  after  we 
have  been  in  it  for  a  short  time.  The  room  seems  suddenly 
hot,  but,  as  a  matter  of  fact,  if  we  were  to  take  the  tempera- 
ture, we  should  not  find  it  very  much  higher.  We  should, 
however,  find  a  very  great  rise  in  humidity.  This  rise  in 
humidity  is  caused 
by  the  loss  of  water 
from  the  bodies  of 
the  people  in  the 
room  from  their 
breath  and  through 
their  skin.  Since 
the  room  has  more 
moisture  in  the  air, 
it  appears  hotter  to 
the  people  in  it. 
The  ventilation  of 
public  buildings  is 
an  important  mat- 
ter, as  is  the  ventila- 
tion of  our  school- 
rooms.  Heated 
rooms  are  sometimes 
made  more  comfort- 
able by  the  use  of 

electric  fans,  which  produce  a  circulation  of  air.  Hot  rooms 
in  homes  are  usually  not  humid  enough,  especially  in  build- 
ings heated  by  a  hot-air  furnace.  It  is  always  a  good  plan 
to  keep  pans  of  water  on  the  radiators  and  to  hang  cloths 
so  that  they  dip  into  pans  of  water  near  registers,  for  in 
this  way  the  air  in  the  rooms  is  more  humid  and  much  more 
healthful.  With  higher  humidity  in  the  rooms  of  a  house 


Wet- and  dry-bulb  thermometers  and  hair  hygrometer : 
useful  instruments  in  determining  humidity. 


88   THE  WEATHER  AND  THE  WEATHER  BUREAU 

one  can  be  comfortable  at  a  lower  temperature  and  one  is 
much  less  likely  to  take  cold  upon  going  out  of  doors. 
A  relative  humidity  of  60%  to  70%  is  desirable  in  the 
house.  Humidity  is  important  in  many  industries.  In 
weaving  cotton  cloth,  the  threads  break  more  easily  in 
dry,  cold  air  than  in  warm,  moist  air,  hence  a  high  humid- 
ity is  maintained  artificially  in  the  weaving  rooms.  On 
the  other  hand,  the  drying  of  clothes,  making  hay,  and  other 
processes  are  carried  on  better  when  there  is  a  low  humidity. 
How  we  measure  humidity.  —  The  amount  of  water 
vapor  in  the  air  is  measured  by  means  of  the  wet-  and  dry- 
bulb  thermometers,  or  hygrometer.  This  instrument  really 
consists  of  two  thermometers,  the  bulb  of  one  being  kept 
moist  by  a  porous  wick.  The  evaporation  of  water  from 
the  cloth  around  the  wick  cools  the  mercury,  and  the 
more  rapid  the  rate  of  evaporation,  the  more  rapidly  the 
mercury  will  fall  and  the  greater  will  be  the  difference  be- 
tween the  two  thermometers.  If  the  two  thermometers 
read  the  same,  it  is  evident  that  the  air  has  all  the 
moisture  it  can  hold,  or  100  per  cent,  as  no  evaporation 
can  take  place.  The  difference  between  the  two  ther- 
mometers is  an  index  to  the  humidity.  It  is  well  to  meas- 
ure the  relative  humidity  of  the  air  in  the  schoolroom,  as 
can  easily  be  done  by  the  following  experiment. 

Experiment.  —  To  measure  the  relative  humidity  of  the  air. 

Materials:  Wet-  and  dry-bulb  thermometers. 

Method:  Wet  the  muslin  covering  the  bulb  and  whirl  the  thermometer 
rapidly  in  the  air  or  fan  a  current  of  air  upon  it,  reading  the  tempera- 
ture. Record  the  lowest  temperature  reached.  Also  record  reading 
of  the  dry- bulb  thermometer.  Refer  to  the  table,  page  89,  and  record 
the  humidity  of  the  air  as  indicated  in  the  table  for  the  readings  noted. 

The  following  table  gives  the  relative  humidity  at  differ- 
ent temperatures  for  given  dry-bulb  readings. 


HOW  WE  MEASURE  HUMIDITY  89 

TABLE  FOR  FINDING  RELATIVE  HUMIDITY.  PERCENTAGES 


Dry 

Therm, 
(air 
temp.) 

Difference  between  Dry-  and  Wet-bulb  Thermometers 

I 

2 

3 

4 

5 

6 

7 

8 

9 

IO 

II 

12 

14 

16 

18 

0 

68 

35 

3 

L 

2 

7i 

41 

12 

4 

73 

46 

19 

6 

75 

50 

25 

i 

8 

77 

54 

31 

9 

10 

79 

57 

36 

15 

12 

80 

60 

41 

21 

3 

14 

82 

63 

45 

27 

10 

16 

83 

66 

49 

33 

16 

0 

18 

84 

68 

53 

38 

22 

7 

20 

85 

70 

56 

42 

28 

14 

22 

.86 

72 

59 

45 

32 

19 

7 

24 

87 

74 

61 

49 

36 

24 

12 

0 

26 

88 

75 

64 

52 

40 

29 

18 

7 

28 

88 

77 

66 

55 

44 

33 

23 

12 

2 

30 

89 

78 

68 

57 

47 

37 

27 

17 

8 

32 

go 

79 

69 

60 

50 

41 

31 

22 

13 

4 

It 

go 

81 
82 

72 
73 

62 
65 

53 
56 

44 
48 

35 
39 

27 
31 

18 

23 

9 
14 

i 
6 

38 

9i 

83 

75 

67 

59 

43 

35 

27 

19 

12 

4 

40 

92 

84 

76 

68 

61 

53 

46 

38 

3i 

23 

16 

9 

42 

92 

85 

77 

70 

62 

55 

48 

41 

34 

28 

21 

14 

0 

93 

85 

78 

71 

64 

57 

44 

37 

31 

24 

18 

5 

46 

93 

86 

79 

72 

65 

59 

53 

46 

40 

34 

28 

22 

10 

48 

93 

87 

80 

73 

67 

60 

54 

48 

42 

36 

31 

25 

14 

3 

50 

93 

87 

81 

74 

68 

62 

56 

50 

44 

39 

33 

28 

17 

7 

52 

94 

88 

81 

75 

69 

63 

58 

52 

46 

41 

36 

30 

20 

10 

Q 

a 

94 
94 

88 
88 

82 
82 

76 

77 

70 

65 
66 

59 
61 

54 
55 

48 
50 

43 

45 

38 
40 

33 
35 

23 
26 

14 
17 

58 

94 

89 

83 

77 

72 

67 

62 

57 

52 

47 

42 

38 

28 

20 

II 

60 

94 

89 

84 

78 

73 

68 

63 

58 

53 

49 

44 

40 

31 

22 

62 

94 

89 

84 

79 

74 

69 

64 

60 

55 

50 

46 

41 

33 

25 

T  *7 

64 

95 

go 

85 

79 

75 

70 

66 

61 

56 

52 

48 

43 

35 

27 

A  / 
2O 

66 

95 

go 

85 

80 

76 

66 

62 

58 

53 

49 

45 

37 

29 

22 

68 

95 

go 

85 

81 

76 

72 

67 

63 

59 

55 

47 

39 

31 

24 

70 

95 

go 

86 

81 

77 

72 

68 

64 

60 

56 

52 

48 

40 

33 

26 

72 

95 

gi 

86 

82 

78 

73 

69 

65 

61 

57 

53 

49 

42 

35 

28 

74 

95 

gi 

86 

82 

78 

74 

70 

66 

62 

58 

54 

44 

37 

76 

96 

gi 

87 

83 

78 

74 

70 

67 

63 

59 

55 

52 

45 

38 

78 

96 

91 

87 

83 

79 

75 

7i 

67 

64 

60 

57 

53 

46 

40 

34 

80 

96 

gi 

87 

83 

79 

76 

72 

68 

64 

61 

57 

54 

47 

41 

84 

96 

92 

88 

84 

80 

77 

73 

70 

66 

63 

59 

56 

50 

44 

8 

88 

96 

92 

88 

85 

81 

78 

74 

67 

64 

61 

58 

52 

46 

* 

9* 
96 

100 

96 
96 
96 

92 
93 
93 

89 
8g 
go 

85 
86 
86 

82 
82 
83. 

78 
79 
80 

75 
76 
77 

72 
73 
74 

69 
70 

65 
67 
68 

62 
64 
65 

59 
61 
62 

54 
55 
57 

48 
50 
52 

41 
43 
45 
47 

90   THE  WEATHER  AND  THE  WEATHER  BUREAU 


Cirrus  clouds ;  found  at  an  altitude  of  five  miles  or  more  above  the  earth. 


Cumulus  clouds ;  often  the  forerunner  of  a  thunderstorm. 


Stratus  clouds ;  low-lying  clouds. 


LOCAL  STORMS  91 

Formation  of  clouds  and  rain.  —  As  the  moist  warm  air 
rises  it  expands.  When  air  expands,  it  becomes  cooler. 
Cooling  air  reduces  its  capacity  to  hold  moisture.  As  a 
result,  at  some  height,  conditions  are  such  that  the  mois- 
ture in  the  air  is  condensed  into  clouds.  The  minute  par- 
ticles of  moisture  in  the  clouds  may  increase  in  size  by  fur- 
ther condensation  upon  them,  or  several  particles  brought 
into  contact  may  unite,  so  that  finally  the  particles  are  too 
heavy  to  remain  suspended  in  the  cloud  and  they  fall  as 
rain. 

A  study  of  the  cloud  pictures  opposite  will  help  us  to  make 
use  of  cloud  observation  in  foretelling  storms.  Cumulus 
clouds,  for  example,  may  bring  local  storms,  especially 
thunderstorms,  but  are  not  an  indication  of  long-con- 
tinued rains.  They  begin  to  form  at  the  level  where  the 
rising  column  of  air  reaches  a  point  where  it  will  con- 
dense, and  frequently  extend  into  the  atmosphere  for 
a  height  of  five  miles  or  more.  Cirrus  clouds  are  light 
and  feathery.  They  are  formed  at  a  very  great  height, 
and  are  usually  composed  of  tiny  crystals  of  ice.  Stratus 
clouds  are  rather  low,  lying  in  long,  horizontal  beds,  and 
are  much  more  likely  to  indicate  rain.  Nimbus  clouds 
almost  always  bring  rain. 

Local  storms.  —  There  are  two  general  types  of  local 
storms,  thunderstorms  and  tornadoes.  The  thunder- 
storms are  common  phenomena  to  most  of  us.  They 
are  rarely  over  twenty  to  twenty-five  miles  in  width  and 
travel  as  a  rule  for  a  distance  of  not  over  one  hun- 
dred and  fifty  to  two  hundred  miles.  The  electrical 
display  depends  upon  the  charging  of  the  air  envelope  with 
electricity.  Electricity  seems  to  be  present  in  the  air  up 
to  a  height  of  many  miles.  During  clear  and  dry  weather 


92   THE  WEATHER  AND  THE  WEATHER  BUREAU 


the  electrical  energy  is  fairly  equally  distributed,  for  dry 
air  is  a  very  poor  conductor  of  electricity,  but  during  rapid 
cloud  formation  great  differences  in  the  electrification  of 
the  air  occur,  and  since  moisture  aids  the  conduction  of 
electricity,  the  result  is  that  a  cloud  may  become  charged 
with  a  bountiful  supply.  The  electricity  is  discharged 
from  the  cloud  by  means  of  the  flash  of  lightning,  either 
to  another  cloud  which  is  oppositely  electrified  or  to  the 

earth  itself.  A  study  of 
the  figure  shows  the  like- 
ness of  the  electric  flash 
to  that  which  is  artifi- 
cially made  in  the  labo- 
ratory. It  is  very  easy  to 
figure  out  how  far  away 
this  discharge  of  elec- 
tricity is  by  observing 
the  flash  and  then  count- 
ing the  number  of  sec- 
onds that  elapse  between 
the  time  of  the  flash  and 

Observe  the  similarity  between  the  natural  and      the  SOUIld  °f  the  thunder , 
the  artificially  made  electric  flashes.  Calculating     that     SOUnd 

travels  to  your  ear  at  the  rate  of  noo  feet  a  second. 
Considerable  damage  is  done  by  thunderstorms,  mostly 
from  burning  barns  and  forest  fires  set  by  lightning. 

Tornadoes.  —  Tornadoes  usually  occur  along  the  valleys 
of  the  Missouri  and  Mississippi  rivers,  and  occasionally 
in  some  parts  of  the  Ohio  Valley,  as  well  as  south  and  east. 
They  are  not  cyclones,  although  often  wrongly  so-called. 
They  are  extremely  local  storms,  frequently  varying  from 
fifty  to  one  thousand  feet  in  width  and  may  travel  dis- 


WINDS  AND  THEIR  CAUSE 


93 


,*„. 


tances  of  from  one  mile  to  twenty  or  thirty,  or,  in  rare 
instances,  to  two  hundred  miles.  A  whirling  motion  de- 
velops in  the  rising  column  of  air,  and  when  of  great  in- 
tensity, the  characteristic  funnel,  which  is  only  a  part  of 
the  cloud  itself,  is  formed.  Air  is  believed  to  rush  around 
in  this  whirlwind  at  the  rate 
of  three  to  five  hundred  miles 
an  hour,  and  wherever  the 
funnel  of  the  tornado  touches 
the  ground,  it  sucks  up  and 
destroys  everything  in  its 
path.  Houses  are  actually 
blown  inside  out,  because 
the  suction  outside  the  house 
causes  the  air  inside  to  blow 
the  walls  and  windows  out- 
wards. Frequently  a  heavy 
fall  of  hail  with  thunder  and 
lightning  accompanies  the 
tornado.  Much  local  dam- 
age is  done  by  these  storms, 
although  fortunately  they 
are  restricted  to  compara- 
tively small  areas. 

Winds  and  their  cause.  - 

If  we  make  a  study  of  the  A  tornado, 

weather  maps   on  pages  96 

and  97,  we  notice  wherever  the  air  pressure  is  low  that  little 
near-by  arrows  point  approximately  toward  that  spot.  If 
we  read  the  map  carefully,  we  see  that  these  arrows  indicate 
that  the  wind  is  moving  spirally  counter-clockwise  around 
this  point  of  low  air  pressure.  This  rotary  movement  around 


94   THE  WEATHER  AND  THE  WEATHER  BUREAU 


and  toward  a  low-pressure  area  is  called  a  cyclone.  Most  of 
our  storms  which  move  across  the  country  in  more  or  less 
regular  paths  are  cyclones.  Areas  of  high  pressure,  known 
as  anticyclones,  show  just  the  reverse  of  the  cyclone  move- 
ment of  air,  the  winds  moving  away  from  these  areas. 
This  cyclonic  movement  of  air  is  sometimes  interfered 
with  by  local  conditions,  such  as  the  unequal  heating  of 

land  and  of  water, 
or  the  presence  of 
hills  and  mountain 
ranges,  which  cause 
them  to  move  in 
irregular  directions. 
Areas  of  low  pres- 
sure have  high  tem- 
peratures and  high 
humidity.  High- 
pressure  areas  have 
low  temperatures 
and  low  humidity. 
Warm  air  is  lighter 
than  cold  air. 
Moist  air  is  lighter  than  dry  air.  These  facts  explain 
in  part  the  existence  of  low  pressures  and  high  pressures. 
The  heavy,  dry,  cold  air  of  the  "  high  "  is  drawn  down  by 
gravity  with  greater  force  than  is  the  moist,  warm  air  of 
the  "  low  "  and  so  the  cold  air  flows  in  under  the  warm 
air  and  lifts  it.  About  the  center  of  the  "  low  "  there  is 
always  an  ascending  current  of  moist  air;  and  about  the 
center  of  the  "  high  "  there  is  a  descending  current  of  dry 
air.  Complete  convection  currents  are  thus  established. 
At  the  surface  of  the  earth  there  is  a  movement  of  air  or 


Explain  these  figures. 


HOW  WIND  VELOCITY  IS  MEASURED  95 

wind  from  the  "  high  "  to  the  "  low."  In  the  upper  layers 
of  air  above  the  earth  there  is  a  current  of  air  from  the 
"  low  "  to  the  "  high,"  thus  completing  the  circuit  of 
moving  air.  Practically  all  of  our  variable  winds  are 
caused  by  natural  convection  currents  in  the  atmosphere. 
The  trade  winds  and  prevailing  westerlies  are  influenced 
largely  by  the  rotation  of  the  earth  in  addition  to  con- 
vection. 
How  wind  velocity  is  measured.  —  Wind  velocity  is 


The  anemometer  determines  wind  velocity. 

measured  by  an  instrument  called  the  anemometer.  This  is 
an  instrument  in  the  form  of  a  spindle,  having  arms  with 
hollow  cups  on  the  end.  The  wind  striking  these  cups 
causes  them  to  revolve,  and  a  certain  number  of  revolu- 
tions per  hour  indicate  one  mile  of  wind  velocity.  The 
following  scale  of  wind  velocity,  called  the  Beaufort  wind 
scale,  issued  by  the  weather  bureau,  will  be  found  useful  in 
working  out  home  projects  on  weather. 


g6   THE  WEATHER  AND  THE  WEATHER  BUREAU 


SCALE  NUMBERS 

KIND  OF  WIND 

MILES  PER  HOUR 

0 

Calm 

From  o  to    3 

i 

Light  air 

Over    3  to    8 

2 

Light  breeze 

Over    8  to  13 

3 

Gentle  breeze 

Over  13  to  1  8 

4 

Moderate  breeze 

Over  1  8  to  23 

5 

Fresh  breeze 

Over  23  to  28 

6 

Strong  breeze 

Over  28  to  34 

7 

Moderate  gale 

Over  34  to  40 

.   8 

Fresh  gale 

Over  40  to  48 

9 

Strong  gale 

Over  48  to  56 

10 

Whole  gale 

Over  56  to  65 

ii 

Storm 

Over  65  to  75 

12 

Hurricane 

Over  75 

Cyclonic  storms.  —  As  we  have  noticed  above,  areas 
of  low  pressure  are  storm  centers.     The  wind  blows  in  a 


Isothermal  Lines 

Isobaric  Lines 

Storm  Track  -»-*jV*"*"* 

Storm  Center      „% 

Clear  O    Partly  cloudy    c   Cloudy  • 

RainR.    SnowS. 

Arrows  point  in  the  direction  wind  is  blowing 

Shaded  areas  show  region  of  precipitation 

during  the  last  2<  hours.  


kLE  OF  MILES  ^^~^^\^ 

*>     *>     *       ^g-C>^^ 


Tell  the  story  of  the  weather  as  disclosed  by  this  map. 

spiral  toward  the  low  in  a  counter-clockwise  direction  in 
the  Northern  Hemisphere,  but  in  a  clockwise  direction  in 


CYCLONIC  STORMS 


97 


the  Southern  Hemisphere.  This  spiral  air  movement  we 
have  called  a  cyclone  and  the  type  of  storm  accompanying 
it,  a  cyclonic  storm.  Cyclones  pass  across  the  United  States 
from  the  northwest,  southeasterly  to  the  Mississippi  Valley, 
then  northeasterly,  usually  leaving  the  continent  along  the 
St.  Lawrence  Valley.  They  move  rather  slowly,  at  the 
rate  of  about  25  miles  an  hour  in  summer  and  about  35 


Isothermal  Lines 

sobaric  Lines  -^-^— 
Storm  Track -»-••*,•»••-. 
Storm  Center      A*M. 
Clear   o    Partly  cloudy  «     Cloudy 
Rain  R.    Snow  S. 

Arrows  point  in  the  direction  wind  is  blowing 
Shaded  areas  show  region  o!  precipitation 
during  the  last  24  hours. 


Weather  conditions  24  hours  later ;  what  important  changes  have  occurred? 

miles  an  hour  in  winter.  These  cyclones  occur  with  con- 
siderable regularity  in  the  winter,  each  cyclone  being  fol- 
lowed by  an  anticyclone  or  area  of  high  pressure,  from 
which  winds  blow  in  a  clockwise  spiral. 

Observation  of  many  weather  maps  will  show  that  the 
southeast  quadrant  of  the  cyclone  is  the  area  most  likely 
to  get  rain.  East  and  south  or  southeast  winds,  unless 
accounted  for  otherwise,  indicate  the  approach  of  a  "  low," 
and  so  frequently  precede  rain  or  snow.  North,  west,  and 

H.    W.   CIV.    SCI.   COMM.  —  7 


98   THE  WEATHER  AND  THE  WEATHER  BUREAU 


View    Vertical^Section. 


northwest  winds,  on  the  other  hand,  follow  the  low  and  pre- 
cede the  anticyclone,  which  brings  cool,  fair  weather.  A 
few  of  the  cyclones  seem  to  originate  in  the  vicinity 
of  the  Gulf  of  Mexico  and  traverse  the  United  States 
in  a  northeasterly  direction.  By  telegraphic  com- 
munication the  progress  and  severity  of  any  storm  can 
be  determined  in  advance.  Sometimes  it  increases  in 
strength,  and  sometimes  its  severity  decreases  as  it  travels 
on  its  way. 

Rain.  —  If  the  temperature  remains  for  some  time  be- 

low the  point  of  conden- 
sation, enough  moisture 
is  formed  to  produce 
clouds  and  rain.  Cyclonic 
storms  as  they  pass  over 
the  country  give  back  to 
the  land  much  of  this 
water  in  the  form  of  rain. 


In  the  far  West  the  storms 
coming  from  the  coast 
lose  much  of  this  water 
in  passing  over  the  moun- 
tain ranges,  so  that  the 
great  plains  east  of  the  Rocky  Mountains  receive  compara- 
tively little  rainfall.  A  study  of  the  map  on  page  17 
shows  that  the  rainfall  differs  very  considerably,  being  as 
high  as  100  inches  a  year  on  some  parts  of  the  Pacific 
Coast,  and  being  reduced  in  some  places  east  of  the  Rocky 
Mountains  to  as  little  as  10  inches  per  year.  Twenty 
inches  a  year  is  a  minimum  for  dry  fanning,  and  a  rainfall 
of  from  30  to  50  inches  is  best  for  the  great  cereal  crops 
of  our  country. 


Horizontal  Sec.  E.F. 


2 13  14  15181718192021222324  inchei 


Scale 

The  rain  gauge.  The  area  of  the  receiver  is 
100  times  the  area  of  the  vessel  in  which 
the  water  is  measured  (C).  Why  ? 


DEW  AND   FROST  99 

Dew  and  frost.  —  We  have  already  seen  that  when  the 
moisture  in  the  clouds  is  condensed,  it  may  form  drops  of 
rain.  In  somewhat  the  same  way  moisture  may  be  con- 
densed on  objects  and  appear  as  dew.  Vegetation,  such 
as  grass,  holds  little  heat,  losing  it  by  radiation  soon  after 
the  sun  goes  down.  The  grass  thus  cools  the  air  immedi- 
ately in  contact  with  it,  and  the  moisture  in  the  air  is  con- 
densed on  the  surface  of  the  blade  of  grass.  When  the 
temperature  of  the  air  is  at  the  freezing  point  or  below  it, 
the  condensed  particles  of  moisture  are  frozen  into  small 
crystals  of  ice  or  frost.  Frost  is  an  enemy  of  the  farmer, 

U.  S.  DEPARTMENT  OF  AGRICULTURE, 
ATHER    BURE 

CHARLES  F.  MARVIN.  Chiel 


WHITEHALL  BUILDING  V"  °'    UXA  AJXlfllliill    VI     JMnUWUJVJhB,  SATURDAY 

..  SSSS^  WEATHER    BUREAU.  ^^  ,  « 


FOR    NEW    YORK    CITY    AND    VICINITY 


Rain  to-night.  Sunday  fair,  colder.  Moderate  sooth  to  west  winds. 
Minimum  temperature  lo-ntghl  about  36  degrees. 

EASTERN  NEW  YORK:  Rain  to-night,  colder  in  extreme  northern  portion.  Sunday  cloudy  and  colder, 
probably  rain  or  snow  in  north  and  central  portions.  Fresh  south,  shifting  to  west  winds. 

EASTERN  PENNSYLVANIA:  Rain  to-night,  warmer  in  south  portion.  Sunday  generally  fair  and  colder, 
except  probably  rain  or  snow  in  extreme  north  portion.  Moderate  south,  shifting  to  west  winds. 

NEW  jERSEY'.Rain  to-night.     Sunday  fair  and  colder.     Moderate  to  fresh  south,  shifting  to  west  winds- 

SOUTHERN  NEW  ENGLAND:  Unsettled  to-night  and  Sunday,  probably  rain;  wanner  to-night;  colder 
Sunday- afternoon.  Fresh  south,  shifting  to  west  winds. 

STEAMERS  departing  to-day  for  European  ports  will  have  fresh  south,  shifting  to  west  winds  and  rain 

to  the  Grand  Banks    

Shipments  of  perishable  produce  should  be  prepared  for  the  following  temperatures  Sunday  morning : 

Northern  New  York.  18°  lo  W-          Northern  New  Enirbnd.  18°  to  3X>-          Southern  New  Entfuid.  30°  to  «P-          Wetten  New  York.  Jt"  »  W>- 
Wentern  Pennsrlvinii.  52°  to  4t°—          Extern  Pennsylvinit.  32°  lo  4f°-          New  Jersey.  JJ°  to  W-          +  Indicates  followed  by  winner.  —  Colder. 

A  sample  of  information  distributed  by  mail  by  the  Weather  Bureau. 

and  can  usually  be  predicted  by  the  weather  officials. 
The  United  States  Weather  Bureau,  by  means  of  its  warning 
signals  and  reports,  is  enabled  to  inform  farmers  when  frost 
is  likely  to  occur,  so  that  they  may  take  proper  precautions. 
In  Florida  and  California  where  citrus  fruits  are  grown, 
frost  is  often  kept  away  by  the  burning  at  night  of  many 
smudge  kettles,  which  raises  the  temperature  near  the  plants 
several  degrees.  Delicate  plants  may  be  covered,  and  other 
means  of  fighting  frost  are  used. 


100  THE  WEATHER  AND  THE  WEATHER  BUREAU 

The  work  of  the  weather  bureau.  —  It  can  be  seen  from 
the  foregoing  paragraphs  that  through  telegraphic  com- 
munication with  various  parts  of  the  country  a  weather 
bureau  is  able  to  tell  accurately  what  weather  may  be  ex- 
pected. There  are  a  large  number  of  branches  in  various 
localities,  and  each  day  the  weather  signs,  —  temperature, 
rainfall,  rate  of  wind,  direction  of  wind,  barometric  pressure, 
and  other  necessary  information,  —  are  telegraphed  to  Wash- 
ington and  to  all  the  different  weather  bureaus  through- 
out the  United  States,  where  weather  maps  are  made  within 
an  hour  after  the  time  the  information  is  received.  These 
weather  maps  are  soon  sent  by  mail  to  places  all  over 
the  United  States.  Along  the  coast,  shipping  is  at 
times  at  the  mercy  of  storms.  By  heeding  the  warnings 
sent  out  by  the  weather  bureau,  large  numbers  of  vessels 
and  men  have  been  saved.  Truck  farmers  and  orange 
growers  depend  upon  the  weather  bureau  frost  warnings 
to  protect  their  crops.  Stations  upon  rivers  which  are 
likely  to  have  dangerous  floods  report  water  levels  and 
probable  rise  in  level  from  predicted  storms.  In  the  World 
War,  the  work  of  the  weather  stations  was  of  tremendous 
importance  in  determining  the  feasibility  of  air  and  gas 
attacks,  as  well  as  other  movements. 

Advance  information  about  the  weather  is  of  importance 
in  warfare,  in  commerce,  in  industry,  and  to  a  degree  in 
controlling  our  own  daily  activities.  While  it  is  im- 
possible at  present  always  to  make  infallible  predictions, 
yet  in  the  large  majority  of  cases  the  weather  bureau  predic- 
tions are  correct,  and  so  in  general  they  may  be  relied  upon. 

The  score  card.  —  Climate  and  weather  are  advantages 
or  disadvantages'that  we  are  not  apt  to  think  much  about. 
Many  large  cities  are  at  a  great  disadvantage  in  this 


THE  SCORE  QARDf 


respect,  and  yet  have  become  great  centers  of  wealth 
and  industry.  Study  temperature,  rainfall,  and  other 
conditions  and  see  how  your  community  scores. 

SCORE  CARD.    CLIMATE  AND   WEATHER  OF  MY  COMMUNITY 


PER- 
FECT 
SCORE 

M 
SCORE 

Extremes  in  yearly  range  of  temperature  not  below 
o°  nor  above  95°  (20),  below  -15°  or  above  100° 
(15),  below  —25°  or  above  102°  (10),  below  —35° 
or  above  105°  (5) 

20 

Sunshine  60%  of  days  (20),  50%  (16),  40%  (12), 
30%  (10),  20%  (8).  Consult  sunshine  map,  page  71 

20 

Rainfall  30  to  60  inches  do),  20  to  30  or  over  60 
inches  (5).  See  map,  page  17. 

10 

No  tornadoes  (10),  infrequent  (2),  frequent  (o) 

10 

No  danger  from  lightning  (10),  infrequent  (2),  fre- 
quent (o) 

IO 

No  long  periods  of  severe  heat  or  severe  cold  (10), 
infrequent  (5),  frequent  (o) 

10 

Freedom  from  damage  by  floods  or  excessive  rains 
(10),  floods  very  infrequent  (5),  floods  frequent  (o) 

10 

Freedom  from  excessive  heat,  drought,  high  winds,  or 
early  frosts  (10),  crops  infrequently  damaged  (5), 
frequently  damaged  (o) 

TOTAL 

100 

REFERENCE  BOOKS 

Boy  Scouts  of  America,  Official  Handbook.     Doubleday,  Page  and  Company. 

Caldwell  and  Eikenberry,  General  Science.     Ginn  and  Company. 

Harrington,  About  the  Weather.     The  Apple  ton  Company. 

Houston,  The  Wonder  Book  of  the  Atmosphere.     Houghton  Mifflin  Company. 

Jameson,  Weather  Series  for  the  Amateur.  Taylor  Instrument  Company,  Roch- 
ester, N.  Y. 

Rolt-Wheeler,  The  Boy  with  the  United  States  Weather  Men.  Lothrop,  Lee,  and 
Shepard  Company. 

Smith  and  Jewett,  Introduction  to  the  Study  of  Science.  The  Macmillan  Com- 
pany. 

The  Book  of  Knowledge.     Grolier  Society,  N.  Y. 

Trafton,  Science  of  Home  and  Community.     The  Macmillan  Company. 

Ward,  Climate.     (For  teachers.)     G.  P.  Putnam's  Sons. 

Whitman,  Lightning.  November,  1916.  General  Science  Quarterly,  Salem,  Mas- 
sachusetts. 


i 


PART  III.     WATER  AND  ITS  PLACE 
IN  THE  LIFE  OF  THE  COMMUNITY 

CHAPTER   VI 
THE  RELATION   OF  WATER  TO   POWER 

Problems.  —  i.  To  learn  how  the  earth  holds  water  and 
how  it  loses  it. 

2.  To  understand  what  is  meant  by  water  power. 

3.  To  learn  about  devices  for  utilizing  water  power. 

4.  To  understand  how  some  communities  are  dependent 
upon  water  power. 

Experiments.  —  i.   To  see  which  kinds  of  soils  hold  water  best. 
2.   To  measure  the  horse  power  of  a  motor. 

Project  I.  —  To  STUDY  THE  CHARACTER  or  LOCAL    SOILS   AND 

WATER   TABLE. 

Investigate  and  report  on  the  character  of  the  local  soils  and  the 
probable  rise  and  fall  of  the  water  table  at  different  times  in  the 
year. 

Project  II.  —  A  STUDY  OF  LOCAL  WATER  POWER. 

1.  To  determine  the  amount  of  water  power  which  can  be  secured 
from  a  small  stream  in  your  vicinity. 

2.  To  investigate  and  report  on  types  of  water  power  plants  near 
your  home.     What  would  work  done  cost  if  gas  or  coal  were  used? 
Is  city  water  supply  used  for  power  ? 

The  earth  a  sponge.  —  During  a  heavy  shower  we  have 
all  seen  large  quantities  of  water  fall  to  the  earth  and 

102 


GROUND  WATER  AND  THE  WATER  TABLE        103 


quickly  disappear.  It  goes  without  saying  that  rain 
water  soaks  into  the  ground.  Millions  of  little  particles 
of  earth  become  covered,  each  with  a  film  of  water.  In 
wet  weather  every  space  between  the  particles  is  also 
filled  with  water,  and,  in  time  of  heavy  rains,  this  water, 
as  we  know,  runs  off  and  fills  our  streams  and  ponds  with 
its  load  of  mud. 

However,  in  a  wooded  country  we  do  not  see  this  effect. 
The  water  seems  to  sink  into  the  soil  and  disappear  be- 
neath the  coating  of  leaf 
mold  and  mosses  which 
covers  the  ground.  This 
material,  with  the  tan- 
gle of  roots  of  trees  and 
the  luxuriant  vegetation, 
holds  water  in  the  soil. 

Experiment.  —  To  see  which 
kinds  of  soils  hold  water 
best. 

Materials:  Three  straight 
lamp  chimneys.  Cheese- 
cloth. Sandy  gravel,  sand, 
and  clay.  Three  glasses. 

Method:  Tie  two  thicknesses  of  cheesecloth  over  one  end  of  each  of  the 
chimneys.  Fill  each  to  the  same  level  (f  full)  with  the  three  kinds  of 
soil  respectively.  These  should  be  dry.  Support  each  of  these  over  a 
glass  tumbler.  Pour  the  same  amount  of  water  into  each  chimney. 
After  all  three  of  the  soils  have  become  saturated  and  all  the  water  has 
run  through  that  will,  measure  the  water  that  has  passed  through. 

Results:  Which  soil  holds  the  most  water?     Which  the  least? 

Application:  What  are  the  advantages  and  disadvantages  of  each  of  these 
types  of  soils? 

Ground  water  and  the  water  table.  —  A  vertical  sec- 
tion through  any  part  of  the  earth's  surface  shows  layers 
of  different  kinds  of  material  before  we  come  to  the  bed 


104 


THE  RELATION  OF  WATER  TO  POWER 


rock  of  which  the  earth  is  mostly  made  up.  At  a  varying 
depth  below  the  surface  the  absorbed  water  becomes  so 
plentiful  that  it  fills  all  the  spaces  between  the  soil  particles. 
It  is,  indeed,  a  great  underground  lake,  although  it  only 
occupies  the  spaces  between  the  particles  of  soil.  This  is 
called  the  ground  water.  The  water  table  or  surface  of  the 
ground  water  may  vary  with  the  season,  sinking  deeper  in 
dry  weather.  It  follows,  in  a  general  way,  the  level  of  the 
land  surface  above  it.  When  we  dig  a  well,  it  fills  up*  to 
the  level  of  this  water  table.  In  parts  of  the  country 


Water  table  and  ground  water. 

where  numerous  little  lakes  exist,  it  is  the  ground  water 
coming  to  the  surface  of  the  land.  Beneath  the  ground 
water  an  impervious  layer  which  does  not  let  water  through 
will  usually  be  found ;  this  tends  to  keep  the  water  from 
sinking  deeper  into  the  earth  at  this  spot. 

Springs  and  artesian  wells.  —  Frequently  the  ground 
water  flows  into  valleys,  there  to  gush  out  as  springs. 
A  glance  at  the  diagram  on  page  105  will  show  how  this 
comes  about.  If  the  spring  gushes  out  under  pressure, 
we  may  be  sure  that  it  has  traveled  from  a  higher  level. 
When  an  artesian  well  is  bored  deep  into  the  ground,  then 
some  deep  supply  of  ground  water  which  has  been  held 
between  two  impervious  layers  is  tapped.  This  may 


COMMUNITIES  AND  WATER  POWER 


105 


have  traveled  many  miles  from  land  of  a  higher  level,  and 
now  bursts  to  the  surface  as  a  fountain.  A  very  famous 
region  of  such  spouting  wells  is  found  in  the  eastern  part 
of  South  Dakota.  This  water  comes  from  a  porous  sand- 
stone which,  though  far  underground  here,  soaked  into 
the  ground  in  the  Black  Hill  District  about  1000  feet  above 
the  altitude  of  eastern  Dakota. 

Communities    and    water    power.  —  Our   knowledge  of 
geography  has  shown  us  that  water  plays  an  important  part 


Conditions  making  an  artesian  well  possible. 

in  the  location  of  towns  and  cities.  Every  boy  and  girl 
knows  that  large  cities  like  London,  New  York,  San 
Francisco,  and  Chicago  owe  their  growth  to  the  fact  that 
they  are  located  on  navigable  bodies  of  water.  Many 
towns  have  come  into  existence  because  of  the  force  of 
running  water.  Any  one  who  has  traveled  through  New 
England  has  noticed  time  and  again  that  flourishing 
towns  and  cities  have  grown  where  falls  in  a  river  occur  and 
where  man  has  built  a  dam  on  the  stream  in  order  to  develop 
water  power.  The  reason  for  this  is  obvious:  here  is 
power  to  do  work  secured  by  man  at  a  cheaper  price  than 


io6         THE  RELATION  OF  WATER  TO  POWER 


it  can  be  obtained  somewhere  else  where  water  power  is 
not  found. 

Water  power.  —  We  use  the  term  "  water  power  "  in  a 
general  way.  We  shall  soon  learn  what  it  really  means. 
We  know  that  by  means  of  this  force  held  by  the  current 

of  a  river  or  mountain 
stream,  wheels  may  be 
turned  and  electricity 
generated.  What  boy 
does  not  know  of  Niag- 
ara Falls  with  its  500,- 
ooo  horse  power  devel- 
opment, of  the  Keokuk 
dam  on  the  Mississippi 
with  its  150,000  horse 
power  turbines,  or  of 
the  great  Norwegian 
water  power  plants  with 
over  500,000  horse 
power  already  in  use ! 
When  we  read  that  it  is 
estimated  that  5,000,000 
horse  power  of  water 
goes  over  Niagara  Falls 
every  hour,  we  realize 
how  important  this 
energy  is  to  the  country.  And  when  we  remember  further- 
more that  this  power  maybe  sent  hundreds  of  miles  by  means 
of  wires,  and  that  within  500  miles  of  Niagara  Falls  lives  one- 
half  the  population  of  the  United  States  and  three-fourths 
that  of  Canada,  we  see  the  immense  practical  significance 
of  the  utilization  of  this  water  power. 


Niagara  Falls. 


WHAT  IS  WATER  POWER?  107 

Any  intelligent  boy  or  girl  must  also  remember  certain 
facts  we  have  previously  learned  in  geography  about 
public  supplies  of  coal,  oil,  and  natural  gas.  All  of  these 
supplies  are  exhaustible,  and,  indeed,  at  our  growing 
rate  of  consumption,  will  become  exhausted,  possibly  within 
a  few  centuries.  Water  power  will  then  become  a  very 
important  source  of  energy  for  running  railways,  light- 
ing cities,  and  running  machinery  in  manufacturing  plants 
and  homes,  as  it  is  to  a  limited  extent  to-day.  Water  power 
is  the  cheapest  kind  of  power.  So  long  as  we  have  a  sun, 
evaporation  will  take  place,  rain  will  fall,  and  streams  will 
flow.  The  building  of  a  dam  and  the  installation  of  ma- 
chinery as  an  initial  expense  is  large,  but  the  running  ex- 
penses are  small. 

It  is  estimated  that  in  New  England,  where  flows  what 
is  said  to  be  the  most  completely  developed  river  in 
the  world  (the  Blackstone  River  in  Rhode  Island), 
only  50%  of  the  available  water  power  is  used.  This  is 
largely  due  to  the  fact  that  the  rivers  in  New  England  with 
available  water  power  sometimes  lose  most  of  their  water 
in  summer.  Great  impounding  reservoirs  are  proposed 
which  will  hold  in  reserve  a  supply  of  water  until  it  is 
needed.  It  is  expected  some  day  that  great  central  power 
houses  will  give  most  of  New  England  heat,  light,  and 
power  from  these  rivers  now  only  partially  harnessed. 

What  is  water  power?  —  No  one  who  has  ever  seen  a 
mountain  stream  after  a  heavy  rain  could  fail  to  have 
noticed  that  the  water  was  doing  work.  Big  stones  and 
small  ones,  tree  trunks  and  logs,  all  tear  their  way  down 
stream,  borne  on  by  the  force  of  the  rushing  water.  Visit 
the  seashore  and  notice  the  work  of  waves.  Look  for 
evidences  of  the  power  of  water  in  erosion.  If  you  have 


io8         THE  RELATION  OF  WATER  TO  POWER 


ever  rowed  a  boat  against  a  current,  you  know  the  water 
pushes  you  back,  and  when  you  turn,  the  boat  goes  down 
stream  more  easily.  Water  power  is  force  exerted  by  the 
water  and  can  be  measured  in  terms  of  work  accomplished. 
For  example,  Niagara  River  pours  over  the  falls  every 
hour  22,000,000  tons  of  water,  which,  falling  a  little  over 


Keokuk  dam  across  the  Mississippi,  showing  power  house  and  locks.    It  supplies  St. 
Louis,  144  miles  away,  with  electricity. 

1 60  feet,  gives  rise  to  over  5,000,000  horse  power  of  energy. 
Let  us  remember  that  work,  in  science,  is  the  measure  of 
resistance  overcome  through  space;  the  simplest  example 
is  lifting  something  against  the  force  of  gravity.  Or  we 
may  do  work  by  moving  a  body  along  a  level  surface, 
overcoming  the  resistance  of  friction  in  doing  this.  The 
unit  of  work  is  the  foot  pound.  A  foot  pound  of  work  is 
done  when  we  lift  a  pound  weight  one  foot  or  when  a  pound 
falls  one  foot,  or  when  we  move  a  body  a  distance  of  one 
foot  horizontally  by  using  a  pound  force  in  overcoming 
friction  or  other  resistance.  Power  is  the  rate  at  which  work 


WHAT  IS  HORSE  POWER?  109 

is  performed.  For  example,  a  stream  which  can  turn  a 
given  wheel  100  times  a  minute  has  more  power  than  one 
which  will  turn  it  50  times  a  minute. 

What  is  horse  power?  —  The  term  "  horse  power  "  came 
into  use  in  England  before  the  time  of  steam.  It  was  the 
amount  of  power  based  on  the  amount  of  coal  a  horse  could 


Keokuk  is  the  greatest  power  dam  in  the  world,  being  capable  of  developing,  over 
300,000  horse  power.    It  is  nearly  a  mile  in  length. 

raise  in  a  second.  This  has  come  to  be  used  as  a  unit  of 
power.  One  horse  power  is  550  foot  pounds  of  work  a  sec- 
ond. Thus  we  are  able  to  measure  the  horse  "power  of  a 
stream  by  dividing  the  amount  of  work  the  water  can  do 
per  second  by  550.  This  will  be  understood  if  we  work 
out  the  following  project. 

Project.  To  determine  the  value  of  a  stream  for  water-power.  Suggestions  for 
work:  Measure  depth  and  width  of  stream  at  five  points  from  10  to  20  feet  apart 
so  as  to  get  average  width  and  depth,  then  measure  rate  of  stream  flow  by  placing 
a  cork  on  surface  in  center  and  mark  distance  traveled  in  i  minute.  Repeat  five  times 
for  average.  Suppose  the  average  width  of  the  stream  is  20  feet,  average  depth  is 
i  foot,  average  wate*  flow  2  feet  per  second  with  a  fall  of  i  foot.  A  cubic  foot 
of  water  weighs  62.5  pounds.  Then  weight  of  water  passing  over  a  given  part  of  the 


no         THE  RELATION  OF  WATER  TO  POWER 

stream  would  be  20X1X2X62.5  or  2500  foot  pounds  per  second.  If  conditions 
were  favorable  to  building  a  dam  to  increase  the  depth  of  water  enough  to  give  a 
10  foot  fall,  what  would  be  the  horse  power  developed?  Divide  foot  pounds  per 
second  by  550.  Why?  Would  such  a  plant  be  sufficient  to  run  a  house- lighting 
plant?  Ask  a  local  electrician  if  you  have  obtained  the  horse  power  developed. 

Experiment.  —  To  measure  the  horse  power  of  a  motor. 
Materials:    Motor  (as  sewing  machine  motor).    Two  spring  balances. 

Cord.     Speedometer.     Stop  watch. 
Method:   Lay  a  cord  around  the  grooved  belt  wheel  to  measure  its  cir- 


cumference. Attach  each  end  of  a  strong  3-foot  cord  to  a  spring  bal- 
ance. Loop  the  cord  about  the  wheel  as  suggested  in  diagram.  The 
spring  balances  are  held  perfectly  horizontal.  Start  the  motor.  When 
under  full  speed  one  pupil  keeps  time,  marking  off  minutes.  A  second 
pupil  takes  the  speed  of  the  shaft  to  see  how  many  revolutions  the 
wheel  makes  per  minute.  Two  others  hold  and  read  the  spring  bal- 
ances. 

The  friction  of  the  cord  is  the  "  load  "  or  work  done  by  the  motor. 
The  load  may  be  varied  from  light  to  heavy  by  changing  the  pull  on  the 
balance  having  the  smaller  reading. 

Results:    Calculate   the  amount   of   resistance.     (Balance    (A)  reading 
minus  balance  (B)  reading.) 

Work  done  =  Resistance  (lb.)X distance  (ft.). 

Distance  per  minute  =  Circumference  of  wheelXno.  of  revolutions  per 
minute. 

Horse  power  =  Foot  pounds  of  work  per  minute. 
33000 

Utilization  of  water  power.  —  One  of  the  first  problems 
a  manufacturer  has  to  face,  when  he  locates  on  a  stream, 
is  how  he  can  make  the  best  use  of  the  water  power  at 
that  particular  point.  Several  factors  have  to  be  taken 
into  consideration:  the  fall  at  that  point,  the  amount  of 
water  available,  and  the  steadiness  of  the  flow.  The  first 


WATER  WHEELS 


in 


factor  determines  the  height  and  size  of  the  dam  to  impound 
the  water  of  the  stream.  If  a  natural  fall  is  already  present, 
only  a  diverting  wall  at  the  top  of  the  fall  is  necessary. 
On  a  wide  but  slow-falling  river  a  large  masonry  or  con- 
crete wall  may  be  used  in  order  _^____^_^_ 
to  get  a  sufficient  head  or  fall  of 
water.  The  first  and  second  fac- 
tors together  determine  the  type  of 
water  wheel  to  be  used,  while  the 
third  factor  determines  the  size  of 
the  dam  to  be  built,  for  no  manu- 
facturing project  can  go  on  without 
power  at  all  times. 

Water    wheels.  —  Several   types 
of   water    wheels   are   used. 


Types  of  water  wheels. 


undershot  wheel  is  most  useful  where  a  large  amount 
of  water  is  available  but  where  there  is  little  fall. 
This  is  the  type  seen  in  the  many  old  tide  mills  found 
along  the  Atlantic  Coast,  in  which  water  is  stored  in  a 


112         THE  RELATION  OF  WATER  TO  POWER 

mill  pond  at  high  tide  and  as  the  tide  falls  runs  out  through 
a  narrow  runway  under  the  wheel.  This  type  of  wheel 
is  not  very  efficient,  losing  about  70%  of  the  energy  of  the 
water  stored  above  the  dam.  A  much  more  efficient 
undershot  wheel,  used  when  there  is  a  strong  flow  but  little 
volume  of  water,  is  the  Pelton  wheel,  so  called  after  the 
inventor.  .  Here  water  pressure  is  the  important  factor. 
The  overshot  wheel  is  useful  where  the  fall  is  not  very 
great  and  the  amount  of  water  available  is  not  large.  The 
water  pours  into  a  series  of  box-like  troughs,  the  weight  of 
the  water  turning  the  wheel.  This  wheel  is  very  efficient, 
losing  only  10  to  20%  of  the  power.  The  breast  wheel  is 
like  the  undershot  wheel,  but  since  water  has  some  "fall" 
it  develops  more  power. 

Turbines.  —  To-day  most  of  the  power  utilized  from 
water  is  by  means  of  the  turbine.  Here  a  number  of  thin 
blades,  set  at  an  angle,  catch  the  force  of  the  water.  The 
wheel  is  usually  located  at  the  bottom  of  a  pit  or  shaft. 
The  water,  coming  down  a  pipe  from  above,  enters  the  tur- 
bine case  from  one  side  and  flows  through  the  turbine,  which 
revolves  in  a  horizontal  plane  on  a  vertical  axis.  (See 
figure  on  page  in.)  As  much  as  90%  of  the  energy  of  the 
water  is  utilized  by  this  kind  of  wheel. 

In  all  water  wheels  the  energy  is  transmitted  either  di- 
rectly or  by  cog  wheels  or  belts  to  dynamos  or  machinery. 
The  turbine  is  used  in  most  of  the  large  electric  plants  which 
transmit  the  electricity  to  distant  points  for  running  street 
cars,  electric  lights,  or  operating  machinery. 

The  relation  of  water  power  to  the  growth  of  commu- 
nities. —  No  boy  or  '  girl  who  has  studied  commercial 
geography  can  fail  to  remember  the  numerous  towns  and 
cities  in  our  eastern  and  middle  Atlantic  states  which 


IMPORTANCE  OF  WATER  POWER 


have  come  into  existence  along  streams  and  rivers.  The 
chief  reason  for  the  existence  of  such  places  is  the  presence 
of  water.  Either  this  water  has  been  used  directly  for 
power,  as  we  have  seen  in  the  cases  of  the  Merrimac  River 
in  New  England,  or,  as  in  the  case  of  the  hundreds  of  manu- 
facturing towns  in  Pennsylvania,  the  rivers  have  served 
to  float  barges  or  other  boats 
with  their  loads  of  raw  ma- 
terials or  fuel. 

A  study  of  the  accompany- 
ing diagram  shows  that  a 
number  of  large  and  im- 
portant manufacturing  cen- 
ters have  come  into  exist- 
ence a  relatively  short  dis- 
tance from  the  Atlantic 
Coast  line.  These  places 
are  located  at  or  near  the 
head  of  navigation  of  rivers 
or  in  any  event  at  a  place 
on  the  river  where  water 
power  exists  in  quantity 
sufficient  to  be  used  for  factory  purposes.  These  cities  owe 
their  importance  not  only  to  water  power,  but  also  to  their 
location  on  rivers  which  offer  a  route  for  either  railroads  or 
boats  with  which  to  transport  the  manufactured  products 
to  the  coast  cities  for  export. 

REFERENCE  BOOKS 

Barber,  First  Course  in  General  Science.    Henry  Holt  and  Company. 
Brigham  and  McFarlane,  Essentials  of  Geography.    American  Book  Company. 
Caldwell  and  Eikenberry,  General  Science.    Ginn  and  Company. 
Dryer,  Physical  Geography.    American  Book  Company. 
H.  W.  CIV.  SCI.  COMM. 8 


What  factors  favor  these  cities? 


114          THE  RELATION  OF  WATER  TO  POWER 

Daniels,  Electric  Light  and  Power  from  Small  Streams.  Yearbook,  '1918,  U.  S. 
Department  of  Agriculture. 

Fisher,  Resources  and  Industries  of  the  United  States.     Ginn  and  Compaay. 

Gilbert  and  Brigham,  Introduction  to  Physical  Geography.  D.  Appleton  and  Com- 
pany. 

Hunter,  Laboratory  Problems  in  Ciwc  Biology.     American  Book  Company. 

Lynde,  Home  Water  Works.     Sturgis  and  Walton  Company. 

Smith  and  Jewett,  Introduction  to  the  Study  of  Science.  The  Macmillan  Com- 
pany. 

Tappan,  Children's  Hour,  Vol.  14.    Houghton  Mifflin  Company. 

The  Book  of  Knowledge.     Grolier  Society. 

Williams,  How  It  Is  Done.  (Niagara  Falls  as  Water  Power.)  Thomas  Nelson 
and  Sons. 

Williams,  Romance  0f  Modern  Inventions.    J.  P.  Lippincott  Company. 


CHAPTER   VII 

RELATION   OF   WATER   SUPPLY  TO   FOOD 
PRODUCTION 

Problems.  —  i.    To  learn  the  water  needs  of  food-produc- 
ing plants. 

2.  To  learn  how  plants  use  water. 

3.  To  learn  how  water-soaked  land  can  be  reclaimed. 

4.  To  learn  how  arid  land  can  be  watered. 

Experiments.  —  i.   To  learn  the  water  content  of  some  common  foods. 

2.  To  show  the  effect  of  lack  of  water  on  a  plant. 

3.  To  show  the  effect  of  a  surface  mulch. 

Project  I.  —  To  MAKE  A  COMPARATIVE  STUDY  OF  THE  AMOUNT 

OF  WATER  IN  VARIOUS  FOODS. 

Project  II. — To  INVESTIGATE  THE  POSSIBILITY  OF  RECLAIMING 

SWAMP  LAND  IN  OR  NEAR  YOUR  COMMUNITY. 

Project  III.  —  A  STUDY  OF  DROUGHT. 

Learn  what  crops  in  your  vicinity  sometimes  suffer  from  drought, 
and  consider  possible  means  of  saving  them. 

The  world  is  dependent  upon  water  for  its  food  supply. 

-  If  you  chance  to  visit  the  market  this  morning,  you  will 
doubtless  see  stalls  full  of  fresh  vegetables  and  fruits. 
Others  display  meats  and  fish,  while  in  the  grocery  store 
you  see  nuts,  cereals,  and  many  eatables  displayed.  Have 
you  ever  stopped  to  think  how  dependent  each  one  of  these 
articles  is  upon  water?  Vegetables  are  all  grown  with  a 
great  deal  of  water  in  the  soil,  and  the  great  fertile  farms 
of  the  West  require  from  three  to  four  hundred  tons  of 
water  per  acre  to  raise  their  crops.  The  trees  which  bear 

"5 


n6     RELATION  OF  WATER  TO  FOOD   PRODUCTION 

nuts  and  fruits  send  their  roots  down  deep  in  the  soil 
after  water,  and  the  cattle  and  the  fish  which  furnish  food 
in  their  turn  depend  on  the  water  supply.  Everything  we 
buy  in  the  market  seems  to  have  required  water. 

Experiment.  —  To  learn  the  water  content  of  some  common  foods. 

Materials:  Test  tubes,  potato,  meat,  bread,  cracker. 

Method:  Heat  a  small  piece  of  each  food  in  turn  in  a  dry  test  tube,  care- 
fully observing  the  cold  walls  of  the  tube  for  condensed  moisture. 

Results  and  Conclusion:  From  these  results  would  you  infer  that  most  com- 
mon foods  contain  water  ?  Which  foods  appear  to  con  tain  mos  t  water  ? 


Compare  the  bare  desert  region  with  the  plant-bearing,  well-watered  region. 

Effects  of  differences  in  water    supply.  —  A    traveler 
going  by  train  from  New  York  to  San  Francisco  passes 


PLANT  LIFE  DEPENDENT  ON  WATER  117 

through  very  different  kinds  of  territory.  In  the  East, 
he  sees  rounded  hills  covered  with  forests,  broad,  sloping 
valleys,  beautiful  streams,  fertile  farms,  manufacturing 
cities  and  towns,  and  a  rather  large  number  of  small  lakes 
and  ponds.  Beyond  comes  the  Middle  West  with  its  fer- 
tile acres  of  corn  and  grain,  its  rolling  and  almost  level 
plains.  Then  after  he  speeds  westward  over  the  prairies 
he  comes  to  the  mountains  with  their  rugged  peaks  often 
whitened  with  snow,  and  the  train 
winds  up  through  deep  gorges  cut  by 
water  through  the  mountain  sides.  Per- 
haps he  obtains  glimpses  of  some  of  the 
wonderful  irrigation  projects  which  have 
caused  the  "  desert  valleys  to  blossom  as 
a  rose."  Farther  west  he  passes  great 
stretches  of  desert,  some  of  which  may 
never  become  useful  for  agriculture  be- 
cause of  their  distance  from  sources  of 
water,  and  still  farther  west,  near  the 
Pacific  Coast,  he  finds  a  land  of  vegeta- 
tion once  more. 

Plant  life  dependent  on  water.  — 
Any  one  taking  such  a  trip  cannot  help 
but  be  impressed  with  the  relation  of 
plant  life  to  water  supply.  While  light 
and  favorable  temperatures  are  necessary 
factors  for  the  growth  of  plants,  yet  water  plays  an  equally 
important  part  in  their  lives.  It  is  very  easy  to  prove  that 
plants  seek  water.  An  experiment  with  a  "  pocket  garden  " 
or  with  a  moistened  sponge  shows  that  roots  grow  toward 
the  source  of  moisture.  If  you  plant  bird  seed  or  mustard 
seed  on  the  under  side  of  a  moist  sponge  and  suspend  the 


nS     RELATION  OF  WATER  TO  FOOD  PRODUCTION 

sponge  by  a  string,  you  will  find  that  the  roots  of  the 
young  plants,  instead  of  being  pulled  downward  by 
gravity,  grow  upward  against  it.  Examination  of  the 
roots  of  trees  and  of  some  large  plants  shows  that 
they  grow  downward  many  feet  in  search  of  this  life- 
giving  fluid. 


Effect  of  water  supply  on  trees.    All  these  trees  are  of  the  same  age.    Why  are  th«se 
at  the  left  the  tallest  ? 

Experiment.  —  To  show  the  effect  of  lack  of  water  on  a  plant. 

Materials:  Two  single  plants  (beans  or  other  common  food  plant)  in 
separate  pots. 

Method:  'Water  one  of  the  plants  regularly.  Let  the  other  go  without 
water. 

Results:  What  eventually  happens  to  one  of  the  plants?  Allow  to  re- 
main 24  hours  after  wilting  is  first  noticed.  Then  try  to  restore  by 
watering. 

Application:  What  practical  bearing  do  the  truths  learned  from  this 
experiment  have  on  our  production  of  food? 

It  is  a  matter  of  common  knowledge  that  leaves  of  plants 
wilt  when  they  do  not  have  water.     The  plant  leaves  are 


CONDITIONS  FAVORABLE  FOR  SOME  CROPS       119 

really  held  up  in  part  by  the  water  in  their  cells.  The 
picture  shown  here  gives  a  very  good  example  of  the 
effect  of  water  on  the  growth  of  trees.  The  size  of  the  tree 
depends  very  largely  on  the  amount  of  water  it  receives. 
The  luxuriant  vegetation  of  the  tropics,  where  showers 
occur  almost  daily,  is  characteristic.  Trees,  as  we  know, 
form  thicker  rings  of  growth  in  a  wet  season  than  in  a  dry 
one ;  this  shows  plainly  in  the  cross  section  of  a  log. 

What  the  plant  does  with  the  water.  —  If  we  were  to 
examine  the  structure  of  the  root  of  a  plant,  we  should 
find,  as  we  have  said  before,  that  the  roots  are  covered  with 
millions  of  tiny  projections  called  root  hairs.  These  pro- 
jections are  really  single  cells,  by  means  of  which  the  plant 
absorbs  water.  The  water  is  passed  first  from  cell  to  cell, 
and  later  by  tiny  capillary  tubes  in  the  interior  of  the 
root,  and  finally,  by  means  of  bundles  of  these  tubes,  reaches 
the  leaves  of  the  plant.  The  leaf,  as  we  have  seen,  is  a 
great  food  manufacturer  which  supplies  material  for  the 
growth  of  the  plant.  There,  food  is  made  which  will  be 
sent  to  the  fruit  of  the  plant.  There,  too,  food  which 
later  may  be  stored  in  the  fleshy  roots  of  vegetables  is 
formed.  But  in  order  to  get  the  necessary  raw  materials  to 
manufacture  this  food,  more  water  is  taken  in  than  is  re- 
quired. Much  of  this  water  is  passed  out  through  the 
tiny  holes  in  the  under  sides  of  most  leaves,  into  the  air 
in  the  form  of  vapor,  which  helps  to  equalize  the 
climate,  and  makes  the  presence  of  plants  desirable  where 
people  live. 

Conditions  favorable  for  some  crops.  —  As  we  take  our 
trip  across  the  continent  we  cannot  fail  to  notice  that 
our  country  is  favored  with  crops  in  great  variety. 
To  the  south  and  in  the  far  southwest  we  have  some 


120     RELATION  OF  WATER  TO  FOOD  PRODUCTION 


tropical  fruits  and  fiber  plants:  we  have  the  apples  of 
Oregon  and  New  York,  we  have  the  sugar  cane  of  the 
South,  and  we  have  the  wheat  and  the  corn  of  the  great 
Northwest.  It  is  evident  that  variation  in  climate  as  well 
as  differences  in  water  supply  are  responsible  for  these 
different  kinds  of  crops.  Wheat,  for  example,  needs  a 
cool,  moist  growing  season,  and  a  warm  ripening  season; 


Harvesting  wheat. 

corn  needs  a  longer  and  warmer  growing  season  than  wheat, 
and  is  very  dependent  upon  water  supply.  Oats  as  well 
as  barley  and  rye  are  more  hardy  and  take  a  damp  and 
cool  climate.  Rice  is  a  water-loving  plant,  and  thrives 
best  in  a  warm,  wet  climate,  while  grass,  the  king  among 
crops  in  this  country  because  of  its  importance  as  food  for 
animals,  seems  to  thrive  with  a  moderate  supply  of  water 
and  can  even  withstand  considerable  drought.  In  the  case 


SNOW    IN    RELATION    TO    CROPS 


121 


of  some  of  the  sugar-producing  plants,  we  find  that  sugar 
cane  requires  a  deep,  moist,  and  well-drained  soil  and  a  long 
hot  season,  but  the  sugar  beet  grows  in  a  cooler  climate, 
and  requires  much  less  water. 

Snow  in  relation  to  crops.  —  We  do  not  always  think  of 
snow  as  favorable  for 
the  growth  of  plants, 
yet  directly  and  in- 
directly it  plays  a 
very  important  part. 
Snow  on  the  sides  of 
the  mountains  packs 
down  into  the  great 
glaciers  which  form 
the  sources  of  some 
of  our  important 
rivers  in  the  West. 
It  thus  helps  to 
regulate  the  water 
supply  during  the 
hot  and  dry  sum- 
mer. In  winter  it 
covers  fields  and  gar- 
dens with  a  blan- 
ket of  insulating 
material,  thus  pro-  A  com  field, 

tecting     seeds     and 

tender  plants  in  the  ground  underneath  from  great  changes 
in  temperature.  In  the  northern  part  of  the  country  it 
must  help  as  well  to  protect  the  bacteria  in  the  soil  and  keep 
them  alive  over  the  long,  cold  winters.  Thus  snow  serves 
an  important  purpose,  especially  in  the  North 7  where  the 


122     RELATION  OF  WATER  TO  FOOD  PRODUCTION 

temperature  frequently  goes  to  forty  degrees  below  zero  in 
winter. 

The  reclamation  of  swamp  areas.  —  Some  of  the  richest 
land  in  the  United  States  is  now  under  water.  The  United 
States  Government  Reclamation  Service  estimates  that 


Swamp,  before  and  after  draining. 

there  are  one  hundred  million  acres  of  undrained  swamp 
land  in  the  United  States  that  will  some  day  be  available 
for  use.  This  land,  when  drained,  becomes  useful  for  inten- 
sive farming  because  of  the  great  amount  of  decayed  organic 
matter  in  the  soil.  Some  of  this  land  has  already  been  re- 
claimed, and  many  thousand  acres  are  being  added  yearly 
by  the  Reclamation  Service.  In  the  Everglades  of  Flor- 
ida, parts  of  which  have  already  been  drained,  some  of  the 
great  drainage  canals  serve  as  a  means  for  transportation. 


DRY  FARMING  123 

Experiment.  —  To  show  the  effect  of  a  surface  mulch. 

Materials:  Two  plants  (beans)  in  separate  pots. 

Method:  Water  them  both  alike  for  several  days.  Sprinkle  them  out  of 
doors  or  let  them  stay  out  during  a  heavy  shower.  After  the  surface 
has  partly  dried,  scratch  the  surface  of  one,  to  loosen  the  surface  layer 
of  soil.  Repeat  this  occasionally  to  keep  a  loose  layer  of  dry  soil  at  the 
surface.  Do  not  touch  the  surface  of  the  other.  Leave  the  two  under 
similar  conditions  protected  from  rains  to  see  which  shows  the  lack  of 
water  first. 

Results  and  Conclusion:  Which  plant  wilts  first ?     Why  is  this? 

Application:  How  can  moisture  in  your  garden  be  conserved  during  a 
dry  season  ? 

Dry  farming.  —  A  study  of  the  map  showing  rainfall  in 
the  United  States  on  page  17  shows  that  a  very  large  part 
of  our  western  states  do  not  get  enough  rain  to  support  crops. 
The  rain  that  does  fall  is  soon  lost  by  direct  evaporation 
from  the  ground.  To  overcome  this  difficulty  farmers  are 
beginning  to  practice  what  is  known  as  dry  farming.  To 
do  this  they. must  first  plow  the  ground  deep  so  that  when 
the  rain  comes  the  ground  will  be  ready  to  soak  it  up  and 
retain  it.  Then  the  surface  layer  of  the  ground  must  be 
constantly  worked  and  turned  over  so  as  to  form  a  surface 
mulch.  This  is  done  by  making  a  layer  of  very  finely 
pulverized  soil  on  top. 

Ground  water  travels  upward  from  particle  to  particle 
by  capillary  action.  Compact  soil  allows  water  to  pass 
rapidly  by  capillary  action  to  the  surface,  where  it 
escapes  by  evaporation.  Breaking  up  the  soil  so  that  the 
particles  lie  loosely  together  prevents  this  action.  Crops 
requiring  little  moisture  are  grown.  Alfalfa,  with  its 
long  roots,  reaches  the  deep-lying  ground  water  and 
adds  to  the  soil  fertility  by  means  of  its  bacteria.  Hard 
wheat,  kafir  corn,  millet,  and  other  crops  may  also  be 
grown.  In  some  places  farmers  can  only  grow  one  crop 


124     RELATION  OF  WATER  TO  FOOD  PRODUCTION 


every  other  year  because  of  the  small  amount  of  water. 
In  such  cases,  the  farmer  keeps  half  of  his  land  under 
cultivation,  and  the  other  half  covered  with  a  surface 
mulch  so  as  to  allow  it  to  accumulate  water. 

Irrigation  and  irrigation  projects.  —  Irrigation  has  been 
practiced  from  the  early  times  of  civilized  man.  If  water 
is  not  present  in  soil,  then  it  may  be  brought  there  by  means 


Roosevelt  Dam  conserves  billions  of  gallons  of  water  for  irrigation  purposes. 

of  canals.  It  has  been  found  that  there  is  much  rich  al- 
luvial soil  in  the  West  which  would  be  valuable  if 
water  could  be  supplied  to  it.  This  was  found  to  be  true 
in  Utah,  and  when  the  first  Mormons  settled  there,  they 
brought  water  from  the  Wasatch  Mountains,  thus  enabling 
the  early  colonists  to  cultivate  gardens.  In  Utah  many 
private  irrigation  canals  were  built  prior  to  1912.  Then 
the  United  States  Irrigation  Service  was  organized,  thanks 
to  the  farsightedness  of  Theodore  Roosevelt.  The  stories 


IRRIGATION  AND  IRRIGATION  PROJECTS          125 

of  the  work  done  by  some  of  these  government  engineers 
in  exploring  and  planning  for  the  diversion  of  water  into 
some  of  these  territories  are  well  worth  reading.  Take, 
for  example,  the  story  of  the  Heroes  of  the  Gunnison 
Tunnel,  by  A.  W.  Rolks,  and  realize  what  dangers  these 


Map  of  irrigation  projects.    National  projects  are  indicated  by  the  solid  black. 

daring  men  of  iron  had  to  undergo  before  a  tunnel  from  the 
Gunnison  River  to  the  Uncompahgre  Valley  could  be- 
come a  reality.  This  project  alone  changed  200,000  acres 
of  desert  land  into  a  fertile  valley  with  towns  having  a 
population  of  over  250,000  people. 

A  study  of  the  map  gives  some  idea  of  the  number  of 


126     RELATION  OF   WATER  TO  FOOD   PRODUCTION 


projects  finished  and  planned.  Over  eleven  million  acres 
of  land  at  the  present  time  are  thus  artificially  watered, 
and  more  projects  are  contemplated,  which  will  make 
more  land  useful  for  farming.  Great  dams  have  been  built, 


What  irrigation  does  for  a  dry  region.    Above  :  first  day  on  the  homestead. 
Below :  same  place  six  years  later. 

and  are  being  erected,  which  will  hold  the  water  from  the 
melting  snow  for  use  during  the  hot  dry  months,  allowing 
it  to  be  distributed  by  means  of  canals  to  the  surrounding 
desert  country.  Some  of  these  canals  are  over  a  hundred 
miles  in  length,  and  hav.e  many  small  branches,  which  in 


IRRIGATION  AND  IRRIGATION  PROJECTS        127 

turn  lead  into  ditches,  feeding  the  land  with  the  much- 
needed  water.  As  a  result  of  irrigation,  land  becomes 
worth  from  sixty  to  three  hundred  dollars  an  acre. 
Through  irrigation  large  crops  of  wheat  are  raised;  po- 
tatoes, onions,  cabbages,  and  garden  truck  of  all  kinds 
are  grown ;  sugar  beets  and  especially  alfalfa  and  grasses 
are  raised  in  great  abundance.  Wonderful  orchards,  es- 
pecially of  apples,  have  come  into  existence  in  Colorado 
and  Oregon.  Because  of  the  intensive  farming  prac- 
ticed, people  live  close  together  and  have  all  the  comforts 
of  community  life,  for  these  irrigation  projects  furnish 
water  power,  which  in  turn  is  changed  into  electricity  and 
used  for  manufacturing  purposes.  Irrigation,  then,  has 
become  one  of  the  greatest  boons  the  West  has  ever  had. 

REFERENCE  BOOKS 

Barber,  First  Course  in  General  Science.    Henry  Holt  and  Company. 

Chamberlain,  North  America.  (Work  of  the  Reclamation  Service.)  The  Mac- 
millan  Company. 

Dryer,  Elementary  Economic  Geography.    American  Book  Company. 

Gruenberg,  Elementary  Biology.    Ginn  and  Company. 

Hunter,  A  Civic  Biology.    American  Book  Company. 

Hunter,  Laboratory  Problems  in  Civic  Biology.    American  Book  Company. 

Sanford,  The  Story  of  Agriculture  in  the  United  States.  D.  C.  Heath  and  Com- 
pany. 

Smith  and  Jewett,  Introduction  to  the  Study  of  Science.  The  Macmillan  Com- 
pany. 

U.  S.  Dept.  of  Agriculture,  Reclamation  Service  Publications. 


CHAPTER  VIII 
RELATION   OF  WATER   SUPPLY  TO   FORESTS 

Problems.  —  i .  To  learn  the  part  water  plays  in  tearing 
down  and  building  up  the  land. 

2.  To  learn  the  effect  afforests  upon  a  water  supply. 

3.  To  learn  where  the  forest  regions  of  the   United  States 
are  located. 

4.  To  understand  why  a  community  needs  trees. 

Experiments.  —  i.  To  show  the  solvent  power  of  water  containing 
carbon  dioxide. 

2.  To  compare  the  water-holding  power  of  leaf  mold  and  sand. 

Project  I.  —  To  IMPROVE  COMMUNITY  TREES. 

Investigate  and  report  on  what  the  community  is  doing  to  in- 
crease the  number  of  trees  and  to  protect  existing  trees.  To  organize 
and  carry  out  a  tree  planting  campaign  in  my  community. 

Project  n. — INVESTIGATE  THE  PUBLIC  USE  OF  GOVERNMENT 
RESERVES. 

Find  out  what  use  my  family  might  make  of  the  government 
forest  reserves  and  the  conditions  under  which  we  could  use  them. 

Project  III.  —  To  MAKE  A  COLLECTION  OF   USEFUL  PRODUCTS 

DERIVED  FROM  TREES. 

Project  IV.  —  To  FIND  OUT  WHAT  TRAINING  I  NEED  TO  BECOME 

A  FORESTER  AND  WHAT   A   FORESTER'S   DUTIES   ARE. 

Forests  and  water.  —  No  boy  or  girl  who  has  been 
fortunate  enough  to  travel  across  the  continent  can  have 
forgotten  the  western  deserts  with  their  miles  and  miles 
of  sand  and  trackless  wastes.  One  cannot  help  com- 
paring the  rich  and  level  plains,  covered  as  they  are  with 

128 


WATER  AS  AN  UNDERGROUND  SOLVENT        129 

vegetation,  with  the  forests,  rivers,  and  hills  of  the  East 
or  far  western  parts  of  the  country.  The  forests  have  a 
beauty  of  their  own,  and,  as  we  shall  see  in  this  chapter, 
play  a  very  important  part  as  well  in  serving  to  regulate 
the  supply  of  water.  When  we  realize  that  over  eighty- 
two  million  dollars'  worth  of  damage  was  done  in  1902 
by  floods  in  the  lower  Mississippi  Valley,  and  that  every 
year  our  farms  lose  from  one  to  two  million  tons  of  their 
most  fertile  soil  which  is  washed  from  their  surfaces  into 


A  break  in  the  levee  on  the  lower  Mississippi. 

the  rivers,  then  we  begin  to  realize  the  value  of  forests  as 
a  national  and  community  asset. 

The  climate  also  is  regulated  to  a  certain  extent  by 
forests ;  for  plants,  as  we  have  seen,  give  off  a  large  amount 
of  moisture  into  the  atmosphere,  and  wherever  they  are 
we  are  apt  to  find  bodies  of  water,  especially  many  small 
lakes,  which  render  the  climate  more  even  and  pleasant. 
To  understand  better  the  value  of  forests,  let  us  first  see 
what  water  has  done  in  making  over  the  surface  of  the 
land  through  which  it  flows. 

Water  as  an  underground  solvent.  —  We  use  water  in 
washing  to  dislodge  and  remove  certain  substances.  We 

H.   W.   CIV.    SCI.   COMM.  Q 


130    RELATION  OF  WATER  SUPPLY  TO   FORESTS 

dissolve  sugar  in  water  in  making  lemonade.  But  we 
sometimes  forget  that  water  is  also  dissolving  materials 
as  it  passes  through  the  soil  and  rocks.  Many  of  us  have 
tasted  mineral  waters;  these  are  waters  which  have  dis- 
solved mineral  material  as  well  as  gases.  Vichy  in  France 
and  Saratoga  in  this  country  are  well-known  examples  of 
places  in  which  are  located  mineral  springs  having 
medicinal  properties.  In  such  waters  the  carbonic  acid 
gas  acts  upon  some  of  the  solid  minerals,  causing  them  to 
dissolve  in  the  water,  while  other  minerals  are  dissolved 
by  water  alone. 

Experiment.  — •  To   show  the   solvent  action   of   water   containing   carbon 
dioxide. 

Materials:  Limestone,  hydrochloric  acid,  test  tubes,  glass  tubing,  a  r,-hole 
stopper,  and  limewater. 

Method:  Generate  carbon  dioxide  by  adding  dilute  hydrochloric  acid  to 
a  few  lumps  of  limestone  in  a  test  tube.  Pass  the  gas  by  means  of  a 
delivery  tube  into  half  a  test  tube  of  limewater.  The  white  pre- 
cipitate formed  is  just  the  same  chemical  substance  as  the  original 
limestone. 

Result:  Will  the  "  precipitated  limestone"  dissolve  in  water?  Will  it 
dissolve  by  continuing  to  pass  carbon  dioxide  into  it?  Try  it.  What 
is  the  effect  of  heating  the  clear  solution? 

Application:  How  can  these  facts  be  applied  to  explain  the  formation  of 
limestone  caves?  To  explain  the  source  of  "  hard  "  water? 

Water  by  its  solvent  action  has  formed  great  caverns 
in  limestone  regions  by  slowly  dissolving  the  rock  along 
its  underground  channels.  Such  a  cave  is  the  Mammoth 
Cave  of  Kentucky.  As  we  have  just  seen,  water  contain- 
ing carbon  dioxide  will  dissolve  certain  mineral  substances. 
The  carbon  dioxide  in  some  water  in  nature  comes  from  the 
decay  or  oxidation  of  organic  materials  in  the  soil.  When 
this  ground  water  flows  through  rocks  which  are  easily 
soluble,  such  as  limestone,  it  becomes  loaded  with  mineral 


WATER  AS  AN  ERODING  AGENT 


Marengo  Cave. 


matter.  Such  waters  we  call  hard.  The  saltness  of  the 
ocean  is  due  to  the  fact  that  the  water  has  brought  sodium 
chloride  in  sufficient 
quantity  to  give  the 
ocean  its  load  of  salt. 

Water  as  a  builder 
of  rock.  —  Water  not 
only  destroys  but  also 
builds  up  rock.  Cer- 
tain soluble  compounds, 
when  brought  together 
in  water,  unite  to  form 
new  insoluble  com- 
pounds. If  water  bear- 
ing such  materials  filters  down  into  cracks  of  rocks,  precipi- 
tation of  these  new  materials  may  take  place,  and  veins  of 
mineral  matter  be  thus  formed.  Precipitation  may  also  re- 
sult from  cooling,  from  evaporation,  and  from  the  loss  of 
some  gaseous  constituent,  as  carbon  dioxide.  In  some  of 
these  ways  veins  of  many  valuable  minerals  have  been 
formed.  Such  are  veins  of  gold,  silver,  and  copper. 

Water  as  an  eroding  agent.  —  Our  physical  geography 
has  shown  us  that  the  contour  of  land  forms  is  largely  due  to 
the  action  of  water.  This  action  is  still  going  on  around  us 
and  may  be  seen  by  any  interested  boy  or  girl.  In  minia- 
ture the  erosive  or  digging  force  of  water  may  be  seen  after 
any  rain.  Notice  how  a  gully  is  formed  on  a  steep  slope 
unprotected  by  trees.  A  study  of  almost  any  embank- 
ment will  show  the  action  of  water,  while  mountain  streams 
and  swift-running  rivers  are  constantly  enlarging  their 
beds  and  are  digging  out  deeper  channels  day  by  day. 
A  current  running  at  one-third  of  a  mile  an  hour  can  carry 


132    RELATION  OF  WATER.  SUPPLY  TO  FORESTS 

clay ;  at  two- thirds  of  a  mile  an  hour,  fine  sand ;  at  two  miles 
an  hour,  small  pebbles  are  rolled  along,  while  at  four  miles 
an  hour  stones  as  large  as  an  egg  are  carried.  Therefore 
streams  which  flow  swiftly  wear  away  their  banks  much 
more  rapidly  than  those  with  slow  motion. 

Water  as  a  land  builder.  —  In  a  similar  manner  rivers 
work  on  a  large  scale.     Sand  and  particles  of  soil  are  torn 


A  deforested  gully. 

out  and  carried  a  long  distance  in  rapidly  flowing  water 
to  be  ultimately  deposited  as  deltas  where  the  current  of 
the  river  is  stopped  by  reaching  ocean  level.  Professor 
Salisbury  of  the  University  of  Chicago  has  estimated  that 
the  Mississippi  River  carries  down  daily  so  much  ma- 
terial that  it  would  take  nearly  900  trains  of  50  cars  each, 
each  car  carrying  25  tons,  to  carry  an  equal  amount  of 
sand  and  mud  to  the  Gulf.  He  estimates  that  all  the  rivers 


CHANGES  IN  LAND  CONTOUR 


133 


of  the  earth  together  daily  carry  to  the  sea  forty  times 
as  much  material  as  does  the  Mississippi.  The  delta 
formed  at  the  mouth  of  the  Mississippi  at  present  con- 
tains almost  as  much  land  as  three  times  the  area  of  Con- 
necticut and  is  growing 
into  the  Gulf  of  Mexico 
at  the  rate  of  one-sixth 
of  a  mile  a  year.  All  the 
area  occupied  by  Loui- 
siana, and  a  large  part 
of  Alabama,  Arkansas, 
Florida,  Mississippi,  and 
Texas,  was  once  a  part 
of  the  Gulf  of  Mexico, 
and  these  states  have 
been  largely  formed  by 
material  which  has  been 
carried  down  by  the 

rivers  flowing  from  the  north.  The  great  glacier  which  cov- 
ered all  the  northern  part  of  the  United  States  at  one  time 
must  have  furnished  an  immense  amount  of  water  and 
billions  of  tons  of  soil  to  the  rivers  which  aided  in  the 
building  of  these  states. 

Changes  in  land  contour  brought  about  by  the  action 
of  running  water.  —  It  is  safe  to  say  that  all  the  valleys 
we  have  seen  or  are  likely  to  see  have  been  made  by  the 
wash  of  running  water.  A  deep  valley  with  steeply  slop- 
ing sides  is  a  young  valley  and  is  still  in  process  of  being 
cut  out  and  deepened  by  the.  action  of  water.  These  valleys 
are  seen  to  best  advantage  in  the  wonderful  canons  of  the 
West.  The  Colorado  River,  for  example,  runs  for  a 
thousand  miles  through  a  gorge  which  has  cut  from  one  to 


Delta  of  the  Mississippi  superimposed  on  the 
state  of  Rhode  Island. 


134    RELATION  OF  WATER  SUPPLY  TO  FORESTS 

several  thousand  feet  through  solid  rock.  Such  a  gorge 
is  of  very  recent  origin  in  geological  times.  On  the  other 
hand,  among  the  valleys  the  rounded  hills  of  New  Eng- 


Contrast  the  steep  walls  of  the  canon  with  the  well-rounded  hills  which  result  from 
long  ages  of  erosion. 

land  are  much  older,  and  have  required  a  longer  period  of 
time  in  being  formed. 

Experiment.  —  To  compare  the  water-holding  power  of  leaf  mold  and  sand. 
Materials:    Two   cylindrical   chimneys.     Cloth.     Beakers.     Leaf   mold 

and  sand. 
Method:   Tie  a  cloth  over  one  end  of  each  cylinder.     Fill  one  cylinder 

half  full  of  leaf  mold  and  the  other  half  full  of  sand.     Pour  equal 

amounts  of  water  upon  these  and  compare  the  amounts  of  water  which 

pass  through,  catching  it  in  beakers. 
Residt:  Which  retains  more  water? 
Application:  Of  what  practical  value  is  this  to  forestry?    To  river  flow? 

The  regulation  and  production  of  water  supply  by  for- 
ests. —  In  the  early  history  of  the  earth,  when  water  did 
its  most  effective  work,  forests  were  not  in  existence, 


REGULATION    OF    FLOODS  135 

and  nowadays  we  find  that  where  forests  are  present, 
more  than  twice  as  much  water  is  held  in  the  soil  as 
where  they  have  been  cut  away.  Trees  form  an  attractive 
covering  for  the  surface  of  the  earth.  Their  roots  and  the 
covering  of  organic  material  which  comes  from  their  dead 
leaves  and  decaying  trunks  and  branches  hold  the  mois- 
ture in  the  ground  by  a  sort  of  surface  mulch  and  prevent 
the  soil  from  washing  away. 

No  one  who  has  tramped  through  the  Adirondack  for- 
ests could  fail  to  notice  the  difference  in  the  streams  there 
and  those  where  the  trees  have  been  cut  off.  The  latter 
have  nearly  disappeared  and  only  dry  beds  are  left  during 
the  hot  weather,  while  in  the  forest-covered  watersheds  the 
streams  are  full  of  crystal  water.  Many  parts  of  the  world, 
especially  China,  Europe,  and  some  parts  of  our  own  coun- 
try, are  now  showing  the  results  of  cutting  off  the  for- 
ests. The  commercial  importance  of  cities  depends  upon 
forests.  Have  you  ever  stopped  to  think  what  might 
happen  to  some  of  our  cities  located  on  or  at  the  mouths 
of  great  rivers  if  the  water  supply  in  these  rivers  could  not 
be  regulated?  In  New  York,  for  example,  should  the 
forest-covered  sources  of  the  Hudson  be  cut  away,  spring 
rains  might  bring  down  millions  of  tons  of  soil  which  would 
eventually  render  the  Hudson  unnavigable,  and  would 
build  up  great  bars  at  the  mouth  of  New  York  harbor 
so  large  that  the  harbor  would  become  closed  up,  and  New 
York  would  lose  its  commercial  importance.  Even  now 
constant  dredging  of  the  channels  leading  through  the  bar 
in  the  lower  bay  is  necessary  in  order  to  keep  it  open  to 
navigation. 

Regulation  of  floods.  —  Each  year,  especially  in  parts 
of  the  earth  where  forests  have  been  cut  down  and  not  re- 


136  RELATION  OF  WATER  SUPPLY  TO  FORESTS 


planted,  millions  of  dollars  of  damage  is  done,  thousands 
of  people  are  rendered  homeless,  and  scores  of  lives  are  lost. 
The  experiment  of  the  United  States  Geological  Survey, 
shown  in  the  diagram  on  this  page,  proves  that  forests 
regulate  floods  by  retaining  the  rainfall.  Usually  rivers 
which  rise  in  hilly  districts  where  the  forests  have  been 
cut  down  receive  the  rainfall  all  at  once  instead  of 


SNOW 


WEEK  3        W£EK  4      WEEK 


WEEK  6. 


la  the  White  Mountains  the  United  States  Geological  Survey  compared  two  areas, 
each  about  5  mi.  sq.  Area  A  was  covered  with  trees.  Area  B  had  no  trees.  A 
weekly  estimate  was  made,  first  of  the  amount  of  snow  that  accumulated  on  the  two 
plots,  then  later  of  the  amount  of  water  that  was  lost.  What  is  the  conclusion  ? 

gradually.  The  result  is  a  freshet  or  flood.  One  of  the 
worst  floods  of  recent  date  was  that  which  isolated  Day- 
ton and  many  other  cities  in  1913.  For  several  days  trans- 
portation across  the  continent  was  interrupted  and  incal- 
culable damage  done.  This  flood  was  caused  by  excessive 
rains  falling  in  a  region  which  had  been  deforested. 

Other  uses  of  forests.  —  Besides  the  regulation  of  water 
supply,  forests,  as  we  have  seen,  make  winters  more  mod- 
erate, and  in  summer  reduce  the  heat  and  lessen  the 
danger  from  storms.  In  some  places  they  serve  as  wind- 


FOREST   REGIONS    OF    THE    UNITED    STATES     137 

breaks,  and  in  many  parts  of  Europe  are  planted  to  pro- 
tect mountain  towns  from  avalanches.  Birds  nest  in 
trees,  and  thus  protect  crops  from  the  ravages  of  insects. 
Trees  also  have  great  commercial  importance,  being  used 
for  lumber,  for  food  production,  and  for  the  extrac- 
tion of  acids,  tar,  creosote,  resin,  turpentine,  and  many 
other  substances  useful  in  everyday  life. 


This  photo  was  taken  in  Macksville,  Indiana,  on  March  28, 1913. 

The  forest  regions  of  the  United  States.  —  The  com- 
bined area  of  the  forests  in  the  United  States,  exclusive 
of  Alaska,  is  about  five  hundred  million  acres,  but  this 
great  area  is  rapidly  decreasing  in  acreage,  owing  to  the 
demands  of  increasing  population,  an  unfortunate  eager- 
ness on  the  part  of  the  owners  of  the  land,  and  wasteful- 
ness on  the  part  of  wood  cutters  and  users  alike.  A  study 
of  the  map  on  page  138  shows  not  only  the  distribution 
of  trees  in  the  United  States,  but  the  principal  types  of 
trees  found.  You  will  notice  that  the  principal  areas  are 
confined  to  the  eastern  and  the  western  coasts,  and  to  that 
region  which  borders  on  the  Great  Lakes. 


138    RELATION  OF  WATER  SUPPLY  TO  FORESTS 


The  forest  regions  of  the  United  States. 

Uses  of  wood.  —  Wood  is  to-day  the  most  used  fuel,  in 
spite  of  coal  and  natural  gas.  It  is  also  the  most  used 
building  material.  It  is  used  as  a  source  of  wood  alcohol. 
Partially  burned  it  becomes  charcoal.  Our  daily  news- 
papers and  our  magazines  are  responsible  for  the  loss  of 
hundreds  of  thousands  of  soft-wood  trees  such  as  spruce, 
hemlock,  balsam,  poplars,  aspens,  and  basswood,  and  un- 
fortunately, young  trees  as  well  as  old  are  sacrificed  for 
this  industry.  The  cone-bearing  trees,  pine,  spruce,  and 
hemlock,  and  especially  the  great  redwoods  of  the  West, 
are  used  for  heavy  construction  work,  frames  of  houses, 
bridges,  masts,  spars,  timber  of  ships,  aircraft,  floors,  wood 
pulp,  railroad  ties,  and  many  other  purposes.  Cedar  is 
used  for  shingles,  cabinet  work,  and  pencils.  Many  kinds 
of  trees  go  into  the  making  of  boxes  for  shipping  purposes, 
it  being  estimated  that  50%  of  all  lumber  cut  finally  is 
used  for  this  purpose.  The  hard  woods,  ash,  beech,  birch, 
cherry,  chestnut,  elm,  hickory,  maple,  oak,  and  wal- 


DESTRUCTION  OF  OUR  FORESTS 


139 


nut,  are  used  largely  for  the  finish  of  our  houses, 
for  the  making  of  furniture,  wagons,  cars,  and  various  other 
purposes. 

Destruction  of  our  forests.  —  As  we  have  just  seen,  the 
great  demands  of  man  are  largely  responsible  for  the  over- 
cutting  of  our  forests,  but  wastefulness  and  carelessness  are 


Unless  checked  early  a  small  fire  may  become  a  disastrous  forest  fire. 

found  at  every  step.  Hundreds  of  thousands  of  dollars' 
worth  of  timber  is  left  each  year  on  the  ground  through 
the  careless  chopping  of  trees  or  the  cutting  of  the  tree 
too  far  from  the  base.  Fire  also  plays  a  prominent 
part  in  the  waste  of  our  forests.  A  study  of  the  causes 
of  forest  fires  shows  that  the  largest  per  cent  is  caused  by 
sparks  from  trains  which  pass  through  the  forests. 
In  New  York  state  laws  have  been  passed  requiring 


140  RELATION  OF  WATER  SUPPLY  TO  FORESTS 

locomotives  to  burn  oil  while  passing  through  forest 
areas.  Carelessness  of  smokers,  hunters,  and  small  boys 
makes  a  large  number  of  fires,  while  burning  brush  and  the 
fires  of  campers  are  responsible  for  others.  "  A  single  tree 
will  make  a  million  matches  but  a  single  match  can  de- 
stroy a  million  trees."  Besides  man,  the  forest  has 
many  natural  enemies.  At  the  present  time  the  nation  is 
fighting  insect  pests,  some  of  which,  as  the  brown-tailed 
moth,  have  been  imported  from  Europe,  and  which  are 
now  threatening  the  destruction  of  many  of  our  northern 
forests.  The  chestnut  canker,  another  imported  plant 
pest,  has  destroyed  nearly  all  of  the  chestnut  trees  in  the 
eastern  part  of  the  United  States,  and  will  probably 
ultimately  destroy  every  live  chestnut  in  the  country,  as 
its  control  is  almost  impossible. 

Some  methods  of  protecting  our  forests:  forestry. — 
For  a  long  time  Europe  has  known  the  value  of  forests  and 
has  taken  means  of  protecting  them.  .  In  Switzerland, 
for  example,  cities  and  towns  have  grown  forests  in  their 
vicinity  for  over  six  hundred  years,  and  have  found  them 
profitable  investments.  The  people  of  this  country  are 
beginning  to  realize  this,  and  we  see  private  individuals, 
corporations,  and  the  state  and  national  governments  all 
engaged  in  taking  means  to  preserve  our  forests.  States 
such  as  New  York  and  Pennsylvania  have  set  apart  tracts 
for  the  growth  of  trees.  The  Adirondack  Park  in  New 
York  contains  nearly  1,500,000  acres  of  timber  land. 
Schools  of  forestry  are  sending  out  young  men  trained  to 
become  foresters.  These  men  are  going  into  the  country 
to  show  that  trees  must  be  planted  where  they  are  cut 
down,  that  trees  must  not  be  cut  until  they  are  "  ripe," 
like  any  other  crop,  and  that  too  thick  a  forest  is  just  as 


FOREST  RESERVES 


141 


bad  as  too  thin  a  forest,  for  then  trees  do  not  get  a  suffi- 
cient amount  of  sunlight  and  plant  food. 

Forest  reserves.  —  In  the  western  part  of  the  United 
States,  as  a  study  of  the  map  will  show,  the  government 
has  set  aside  great  tracts  of  land  in  those  districts  where 
forests  are  needed  to  prevent  the  supply  of  water 
from  quickly  running  off  the  mountains.  These  great 


parks 


This  map  shows  where  our  national  forests  and  parks  are  located. 

national  forests  are  watched  over  by  rangers,  trained  men 
who  move  about  from  place  to  place  protecting  trees  and 
preventing  forest  fires.  They  also  supervise  the  cutting 
of  the  forest  and  planting  where  new  trees  are  needed. 
The  forest  reservations  are  open  to  the  public.  The  gov- 
ernment allows  cutting  of  the  ripe  or  full-grown  trees. 
It  allows  sheep  and  other  animals  to  be  pastured  on  the 
reserve  on  payment  of  a  fee,  and  tourists  and  campers 
have  the  right  to  use  the  forests  as  their  own  under  cer- 
tain controlling  restrictions.  The  government  has  set 


142      RELATION  OF  WATER  SUPPLY  TO  FORESTS 

aside  some  of  the  most  beautiful  areas  in  the  country  as 
national  parks.  The  most  noted  are  the  Yellowstone,  the 
Glacier  National  Park,  and  the  Yosemite  in  California. 

The  community's  need  for  tree  protection.  —  All  of  us 
know  the  value  of  shade  trees.  Many  of  our  best  cities 
are  spending  thousands  of  dollars  each  year  in  planting 
and  protecting  trees.  They  have  set  aside  parks  for 


A  view  in  Mt.  Rainier  National  Park. 

breathing  spots,  knowing  that  trees  give  off  moisture 
and  oxygen  into  the  atmosphere,  and  many  cities  are 
encouraging  school  children  to  help  in  the  protection 
of  these  trees.  City  parks  and  trees  everywhere  attract 
and  afford  nesting  places  for  our  native  birds.  We  should 
do  all  we  can  to  encourage  birds  to  stay  with  us,  both 
by  erecting  bird  houses,  giving  them  food  and  drinking 
places,  and  keeping  the  hunter  cat  from  doing  them  harm. 
Birds  destroy  insects  and  aid  in  making  our  towns  beau- 
tiful. Trees  in  our  city  streets  should  be  protected.  Thou- 
sands of  city  trees  are  killed,  for  example,  by  horses  gnawing 


SCORE  CARD  143 

the  bark.  This  may  easily  be  prevented  by  placing  wire 
guards  around  the  trunks  of  these  trees.  The  city  of  Chi- 
cago, through  its  city  forester,  has  given  the  following 
reasons  why  trees  should  be  planted  in  the  city : 

(1)  Trees  are  beautiful  in  form  and  color,  inspiring  a  constant  appreciation  of 
nature. 

(2)  Trees  enhance  the  beauty  of  architecture. 

(3)  Trees  create  sentiment,  love  of  country,  state,  city,  and  home. 

(4)  Trees  have  an  educational  influence  upon  citizens  of  all  ages,  especially 
children. 

(5)  Trees  encourage  outdoor  life. 

(6)  Tree   purify  the  air. 

(7)  Trees  cool  the  air  in  summer  and  radiate  warmth  in  winter. 

(8)  Trees  improve  climate  and  conserve  soil  and  moisture. 

(9)  Trees  furnish  resting  places  and  shelter  for  birds. 
(10)  Trees  increase  the  value  of  real  estate. 

(n)  Trees  protect  the  pavement  from  the  heat  of  the  sun. 
(12)  Trees  counteract  adverse  conditions  of  city  life. 

Arbor  Day  has  been  set  aside  in  many  states  as  a  day 
for  tree  planting  and  tree  protection. 

An  excellent  home  project  would  be  the  planting, 
care,  and  protection  of  some  one  good,  rapid-growing  tree 
for  your  home  grounds.  Better  yet  would  be  the  or- 
ganization of  a  campaign  of  your  boy  and  girl  friends 
to  plan  for  the  yearly  planting  and  care  of  trees  in 
your  neighborhood;  thus  you  can  make  Arbor  Day  of 
real  practical  use  in  your  community. 

Score  card.  —  This  score  card  includes  items  that  we 
have  been  talking  about  in  the  last  three  chapters.  Water 
supply  and  water  power  are,  after  all,  closely  dependent 
upon  our  forests.  Here  again  your  score  must  be  based 
upon  a  certain  type  of  community  and  not  upon  several 
types.  Therefore  score  only  50  from  items  (i),  (2),  or 
(3),  and  then  the  second  50  from  item  (4),  which  deals  with 
features  common  to  all  communities. 


144     RELATION  OF  WATER  SUPPLY  TO  FORESTS 


SCORE   CARD.    RELATION   OF   WATER  TO   ECONOMIC   LIFE   OF 
COMMUNITY. 

Score  (i),  (2),  or  (3),  and  (4),  making  a  possible  total  of  100  points  for  your  community. 


PER- 

'  FECT 

SCORE 

MY 

SCORE 

I  .    WATER 
POWER 

Over  200,000  horse  power  produced  in  my  community 
(10),  over  100,000  (5),  over  10,000  (3) 
All  water  power  utilized   by  the  community  (10), 
partly  (5),  none  (o) 
Impounding   dams  for   regulation   and   storage   of 
water  (5) 
Many  manufactories  as  result  of  water  power  (15), 
few  (5),  none  (o) 
Electric  light  and  power  cheap  as  result  of  water 
power  (10),  moderate  (7),  expensive  (3) 

50 

2.    AGRICUL- 
TURE 

Farms  well  watered  (10),  moderately  (5),  poor  (2) 
Farm  soil  never  lost  as  result  of  floods  (5),  soil  some- 
times lost  (3),  often  (o) 
Snow  protecting  land  in  winter  (5) 
Farms  workable  from  Apr.  i-Nov.  i   (10),  May  i- 
Oct.  i  (7),  June  i-Sept.  i  (5) 
Rainfall  abundant  (10),  moderate  (7),  scant  (2) 
Reclamation  of  all  swamp  areas  (5) 
Irrigation  of  all  dry  areas  (5) 

50 

3.    FORESTS 

Protection  afforded  against  forest  fires  (10) 
Protected  against  overcutting  (10) 
Forest  reserve  areas  or  large  forests  near  (10) 
Forestry  practiced  by  lumbering  companies  (10) 
River   watershed   protected   by   forests   (10),    few 
trees  (5),  none  (o) 

So 



4.    COMMUNITY 
TREES 

Public  parks  with  many  trees  (10) 
Tree  protection  in  streets  practiced  (10) 
Spraying   (2$),    pruning   (24),  screens   (2$),  tree 
surgery  (24) 
Tree  planting  practiced  (7) 
Arbor  Day  observed  (3) 
Many  trees  on  city  streets  (10),  few  (5),  none  (o) 
Many  trees  in  community  home  grounds  (10),  few 
(5),  none  (o) 

50 

IOO 

TOTAL 

REFERENCE  BOOKS 

Articles  on  Trees  in  City  Streets.    American  City  Magazine. 
Bowman,  Forest  Physiography.     John  Wiley  and  Company 
Bruncken,    North  American  Forests  and  Forestry.     (For  teachers.) 
nam's  Sons. 


G.  P.  Put- 


REFERENCE    BOOKS  145 

Caldwell  and  Eikenberry,  General  Science.     Ginn  and  Company. 
Doubleday,  Birds  Worth  Knowing.    Doubleday,  Page  and  Company. 
Fenno,  Care  of  Trees  in  Street,  Lawn,  and  Park.    Henry  Holt  and  Company. 
Hodge,  Civic  Biology.     Ginn  and  Company. 
Hunter,  A  Civic  Biology.    American  Book  Company. 

Hunter,  Laboratory  Problems  in  Civic  Biology.    American  Book  Company. 
Pinchot,  Primer  of  Forestry.    Farmers'  Bulletin  173,  U.  S.  Dept.  of  Agriculture. 
Rogers,  Trees  Worth  Knowing.    Doubleday,  Page  and  Company. 
Roosevelt  and  others,  Forest  Preservation  and  National  Property. 

Forestry  Circular  25,  U.  S.  Dept.  of  Agriculture. 

Yearbooks  U.  S.  Dept.  of  Agriculture  1895  to  Date.     Look  for  articles  on 

forestry  and  work  of  the  forests. 
Trafton,  Bird  Friends.    (For  teachers.)    Houghton  Mifflin  Company. 


H.   W.   CIV.   SCI.  COMM. IO 


CHAPTER   IX 
THE   COMMUNITY  WATER   SUPPLY 

Problems.  —  i.  To  learn  what  constitutes  a  pure  drinking 
water. 

2.  To  learn  what  are  the  community  needs  of  water. 

3.  To  learn  how  a  community  may  obtain  a  supply  oj 
safe  water. 

4.  To  learn  how  water  is  purified  by  filtration   and  by 
chemical  treatment. 

5.  To  learn  the  proper  care  of  a  public  water  supply. 

Experiments.  —  i.  To  show  the  danger  of  judging  the  purity  of  water 
by  its  appearance,  (i)  Chemical  test.  (2)  Biological  test. 

2.  To  see  what  impurities  are  removed  from  water  by  filtration. 

3.  To  illustrate  gravity  distribution  of  a  water  supply. 

Project  1.  — To  INVESTIGATE  AND  REPORT  ON  THE  PUBLIC  WATER 

SUPPLY  OF  MY  OWN  COMMUNITY. 

Project  n.  —  To  LEARN  ABOUT  THE  WATER  SUPPLY  OF   SOME 

LARGE  CITY. 

New  York,  Cleveland,  Los  Angeles,  or  Philadelphia. 

Water  supplies.  —  It  goes  without  saying  that  a  town  or 
city  could  not  exist  without  drinking  water.  The  people 
of  Greece  or  Rome  and  those  of  other  ancient  cities,  if 
unable  to  obtain  water  on  the  spot  where  they  built  their 
cities,  went  to  great  expense  to  build  long  aqueducts  to 
bring  water  to  their  homes.  The  modern  community,  no 
Less  than  those  of  ancient  times,  has  gone  to  very  great 
expense  and  labor  to  obtain  pure  water.  When  the  Pil- 
grims landed  at  Plymouth,  they  looked  for  a  suitable  place 
to  settle.  An  old  journal  tells  us  that  Captain  Miles  Stan- 

146 


WHAT  IS  PURE  DRINKING  WATER?  147 

dish  and  his  party  "  marched  into  ye  land  and  found 
there  cornfields  and  little  running  brooks,  a  place  fit 
for  a  situation."  So  here,  with  the  "  little  running 
brooks"  for  their  water  supply,  they  founded  their  first 
community. 

What  is  pure  drinking  water  ?  —  We  have  already  learned 
that  water  can  and  often  does  contain  other  matter  than 
what  falls  from  the  clouds  as  rain.  Rain  water,  before  it 
comes  in  contact  with  anything  on  the  earth,  is  practically 
pure  water.  But  water  may  be  perfectly  good  to  drink  and 
contain  mineral  matter  in  solution.  Such  water  is  pure 
as  far  as  necessary  for  drinking  purposes.  Water  which 
contains  organic  matter,  especially  if  there  is  much  decaying 
material  present,  is  not  pure.  Why?  Simply  because  it 
contains  germs.  Decaying  matter  means  the  presence  of 
germs  which  may  be  harmful  to  the  human  body,  hence 
such  water  is  impure  and  unfit  for  drinking  purposes. 
Would  you  be  willing  to  drink  any  water  that  was  clear 
and  sparkling?  The  following  experiment  will  give  you 
a  reason  for  not  judging  by  appearance  alone. 

Experiment.  —  To  show  the  danger  of  judging  the  purity  of  water  by  its 
appearance. 

Materials:  Filtered  salt  water.  Distilled  water.  Solution  of  silver  ni- 
trate. Test  tubes. 

Method:  Observe  how  clear  the  salt  water  is,  add  a  few  drops  of  silver 
nitrate  solution  to  10  c.c.  of  the  water  in  a  test  tube.  Similarly  add 
silver  nitrate  to  distilled  water. 

Results  and  Conclusion:  Compare  results.     Was  the  water  tested  pure? 

(Note:  The  white  cloudiness  produced  when  silver  nitrate  is  added 
to  the  salt  water  is  due  to  the  presence  of  chlorides  in  the  water.  Chlo- 
rides are  in  water  polluted  by  sewage  or  drainage  from  houses.  Polluted 
water  will  usually  show  a  large  number  of  bacteria  when  tested.  When 
a  drop  of  water  is  placed  on  sterile  agar  and  set  away  in  a  warm  place, 
the  number  of  colonies  of  bacteria  which  develop  roughly  indicate  the 
purity  of  water.) 


148  THE  COMMUNITY  WATER  SUPPLY 

Sources  of  water.  —  The  household  which  takes  its 
water  from  a  well  or  spring  has  one  problem.  But  the 
community  which  must  provide  water  not  only  for  drinking 
but  also  for  washing,  street  cleaning,  manufacturing,  and 
fire  protection  has  another.  It  is  evident  that  a  single 
spring  would  not  meet  the  demands  of  even  a  small  com- 
munity. And  even  a  number  of  artesian  wells  rarely  pro- 
vide enough  water  for  a  town  to  use  for  all  its  needs.  So 
the  city  must  depend  largely  upon  surface  water,  streams, 
or  rivers,  the  banks  of  which  are  often  used  for  human 
habitation.  Surface  water,  no  matter  how  careful  people 
may  be,  often  receives  some  drainage  containing  the 
body  waste  of  animals  and  man.  So  our  problem  is  to 
find  out  how  such  water  coming  from  streams  or  rivers  or 
lakes  may  be  made  safe  to  drink. 

Problems  of  water  supply  for  communities.  —  The  need 
of  an  abundant  as  well  as  pure  water  supply  in  a  large 
community  is  most  important.  We  know,  at  the  present 
time,  that  many  cities  are  forced  to  take  their  supply  of 
drinking  water  from  sources  which  are  bound  to  be  con- 
taminated. Take,  for  example,  Buffalo  or  Cleveland,  which 
take  their  water  supply  from  the  lakes  on  which  they  are 
situated,  and  into  which  the  sewers  of  these  cities  flow.  Or, 
take  Philadelphia  or  Pittsburgh,  which  must  draw  their 
supply  from  rivers  which  are  greatly  contaminated  by 
sewage  from  the  many  small  cities  and  towns  located  above 
the  point  from  which  they  take  their  water.  A  third  type 
of  city  might  be  New  York  or  Los  Angeles,  which  have 
no  near  source  of  water  supply  and  must,  in  order  to  get 
an  abundant  supply  of  pure  water,  tap  sources  far  distant 
from  the  city.  For  each  of  these  three  types  of  cities  the 
problem  of  obtaining  a  pure  water  supply  is  quite  different. 


RIVER  WATER  SUPPLY  149 

River  water  supply.  —  For  many  years  cities  which  took 
their  water  supply  from  rivers  had  a  notably  high  typhoid 
death  rate,  and  it  was  not  until  the  year  1891  that  the  reason 
for  this  was  scientifically  demonstrated.  In  that  year, 
Allen  Hazen,  and  a  number  of  experts  on  water  supply, 
made  a  study  of  a  typhoid  epidemic  which  occurred  in  the 
cities  of  Lowell  and  Lawrence,  Massachusetts.  The  city 


In  1891  Lowell  was  supplied  with  unfiltered  water  from  the  Merrimack  River.     Why 
is  such  a  supply  dangerous?     Each  black  dot  represents  a  case  of  typhoid  fever. 

of  Lowell  took  its  water  supply,  without  filtering  it,  from 
the  Merrimack  River  at  a  point  a  few  miles  above  the  city. 
Typhoid  fever  broke  out  in  the  little  hamlet  of  North 
Chelmsford,  a  few  miles  above  Lowell.  About  two  weeks 
later  a  great  epidemic  of  typhoid  broke  out  in  Lowell.  Al- 
most a  month  later  a  similar  epidemic,  although  not  so  great 
in  magnitude,  occurred  in  Lawrence,  about  ten  miles 
further  down  the  Merrimack  River.  A  little  thought  will 


THE  COMMUNITY   WATER  SUPPLY 


show  us  what  happened.  The  typhoid  germs  from  the 
sewage  of  North  Chelmsford  passed  into  the  water  pipes 
of  Lowell  and  were  taken  into  the  bodies  of  the  people  who 
drank  the  water.  The  germs  were  passed  out  from  their 
bodies  in  great  numbers  into  the  sewers  and  thus  down  the 
river  to  Lawrence.  Fortunately  for  the  latter  city,  typhoid 
germs  are  killed  rather  easily,  and  the  exposure  of  the  mil- 
lions of  germs  to  the  air  and  sunlight  as  they  passed  down 
the  river  was  sufficient  to  destroy  great  numbers  of  them. 
But  still  enough  remained  to  cause  the  great  outbreak  of 
typhoid  in  Lawrence. 

This  story  has  been  repeated  with  variations  in  almost 
every  city  or  town  which  has  taken  its  water  unfiltered 
from  streams  into  which  sewage  passes.  Inasmuch  as 
streams  usually  have  more  or  less  sewage  flowing  into  them, 
it  is  evident  that  no  such  water  is  safe  to  drink.  But 
cities  frequently  have  to  get  water  from  this  source.  What 

must  they  do 
to  make  this 
water  safe? 

Filters  and 
filter  beds.— 
The  studies 
of  Hazen 
showed  with- 
out a  doubt 
that  filters  of 
sand  would 
take  out 
enough  germs 

from  contaminated  water  to  make  it  fairly  safe  to  drink. 
A  glance  at  the  accompanying  diagram  shows  the  effect  of 


Cases  of  typhoid  per  100,000  inhabitants  before  filtering  water 
supply  (solid)  and  after  (shaded)  in  A,  Water  town,  N.  Y.; 
B,  Albany,  N.  Y.;  C,  Lawrence,  Mass.;  D,  Cincinnati,  Ohio. 
What  is  the  effect  of  filtering  the  water  supply? 


FILTERS  AND  FILTER  BEDS 


'SA.TJD 


such  filters  in  the  number  of  cases  of  typhoid  in  Watertown, 
Albany,  Lawrence,  and  Cincinnati.  The  number  of 
germs  in  the  water  was  so 
much  reduced  that  only 
about  2%  of  the  origi- 
nal germs  got  through 
the  filters  and  into  the 
pipes  of  the  city.  Con- 
sequently, the  number  of 
typhoid  cases  was  very 
greatly  reduced.  A  study 
of  the  accompanying  dia- 
gram and  picture  will 
give  you  some  idea  of 

how  a  filter  bed  is  made.  You  will  notice  that  the  bed 
consists  of  small  stones,  gravel,  coarse  sand,  and  fine  sand 
in  layers.  If  these  layers  are  of  sufficient  depth  to  allow 


••  -f  "••'  - '  -f  '--  "v    ,--y->o.»3pir 


Structure  of  a  filter  bed. 


A  modern  filtration  plant. 

the  water  to  trickle  through  very  slowly,  they  will  take 
out  about  98%  of  the  germs,  which,  of  course,  are  left  be- 
hind in  the  fine  sand.  Consequently,  in  order  to  make  a 
filter  fit  for  service  a  number  of  beds  must  be  planned  so 
that  certain  ones  of  them  may  be  put  out  of  use  every 


152 


THE  COMMUNITY  WATER  SUPPLY 


few  weeks,  the  sand  removed  or  sterilized,  and  the  filter 
bed  thoroughly  cleaned.  The  installation  of  filter  beds 
is  very  expensive,  but  more  than  pays  for  itself  in  the 
saving  of  human  lives  and  health. 

Experiment.  —  To  see  what  impurities  can  be  removed  from  water  by 

nitration. 

Materials:  Funnel.  Fine  sand.  Powdered  animal  charcoal.  Test 
tubes.  Filter  paper.  Impure  water  containing  a  sulphate  in  solu- 
tion, suspended  matter  (mud),  and  cochineal  (coloring  matter).  Barium 
chloride  solution. 

Method:  (i)  Fill  the  filter  paper  in  the  funnel  nearly  full  of  clean  fine 
sand.  Pour  some  of  the  muddy  water  upon  it  and  catch  the  filtrate  in 
a  test  tube. 

(2)  Boil  a  little  of  the  solution  with  the  powdered  charcoal.     Pour 
it  upon  a  filter  paper  placed  in  a  funnel.     Pour  back  the  first  spoonful 
that  filters  through,  then  catch  the  filtrate  in  a  test  tube. 

(3)  Test  the  filtrate  in  each  case  for  a  sulphate  by  adding  barium 
chloride  solution.     If  it  turns  milky,  the  sulphate  is  present. 

Results  and  Conclu- 
sion: What  are  the 
results  in  each  case? 

Formulate  a 
statement  sum- 
ming up  the  value 
of  filtration  in  puri- 
fying water. 

If  the  water  con- 
tained bacteria 
would  you  expect 
to  find  them  in  the 
filtrate  or  in  the 
sand? 

Use  of  reser- 
voirs. —  An  addi- 
tional protection 
to  water  supplies 
of  this  sort  is  a  reservoir.  Germs  remaining  in  a  large 
body  of  water  for  even  a  relatively  short  period  of  time 


A  comparatively  pure  water  supply. 


LAKE  WATER  SUPPLIES 


153 


lose  their  vitality  and  die.  This  is  due  to  the  fact  that 
they  have  no  food,  for  there  is  no  vegetable  or  animal 
matter  to  feed  upon.  Air  and  sunlight  also  assist  in  the  de- 
struction. Therefore,  any  large  reservoir  holding  a  reserve 
supply  of  water  aids  in  the  destruction  of  germs. 

Use  of  chemicals.  —  Most  water  supplies  which  are  not 
reasonably  pure  are  protected  nowadays,  in  addition  to 
other  means,  by  the  use  of  chemicals.  Bleaching  powder 
and  liquid  chlorine  are  used  very  successfully  and  kill  all 
harmful  germs. 

Lake  water  supplies.  —  Cities  which  take  their  water 


DEATH  RATE 
REDUCED  TO 

7 

,000 


DEATH  RATE 
REDUCED  TO 


Notice  how  deaths  from  typhoid  diminished  upon  the  introduction  of  the  filtration 
plant  and  diminished  again  when  the  use  of  chlorine  was  introduced. 

supplies  from  a  lake  into  which  sewage  flows,  such  as 
Chicago,  Buffalo,  or  Cleveland,  have  frequently  had  a  high 
death  rate  from  typhoid.  In  fact,  in  Chicago  prior  to 
1900  the  average  yearly  death  rate  from  typhoid  was  66.8 
per  100,000.  In  the  next  decade  its  average  was  reduced 
to  22.3  per  100,000.  At  present  its  death  rate  is  less 
than  5  per  100,000.  This  change  was  brought  about  to  a 
large  extent  by  the  digging  of  a  drainage  canal,  which  drew 
the  sewage  of  Chicago  into  the  Chicago  River  and  passed 
it  into  the  Mississippi. 


154  THE   COMMUNITY   WATER   SUPPLY 

A  modern  city  water  supply.  —  The  city  of  New  York 
offers  an  excellent  example  of  a  modern  project  for  the  sup- 
ply of  pure  water  to  a  large  city.  New  York  found  many 
years  ago  that  it  must  go  a  distance  of  about  fifty  miles  from 
the  city  in  order  to  get  a  pure  supply  in  sufficient  quantity 
for  use.  In  1842  it  began  using  water  from  the  Croton 


The  Ashokan  dam,  seen  from  below ;  beyond  it,  hidden  from  view,  is  the  great 
reservoir  of  the  Catskill  water  supply  of  New  York. 

River  some  forty  miles  from  the  city.  Here  a  great  dam 
was  built  across  the  river,  an  aqueduct  constructed,  receiv- 
ing reservoirs  built,  and  a  fine  supply  of  pure  water  was 
thus  obtained.  In  1890  this  system  was  again  enlarged, 
but  after  the  city  grew,  its  needs  became  greater,  and  it 
soon  became  evident  that  it  must  go  farther  away  for 
its  supply  of  pure  water.  So  large  tracts  of  land,  900 
square  miles  in  all,  were  acquired  in  the  Catskill  Moun- 
tains. Great  aqueducts  over  127  miles  in  length  were 
built,  and  the  huge  Ashokan  reservoir  was  constructed 
on  the  Esopus  River.  This  tremendous  undertaking  cost 


PRESSURE  NECESSARY 


155 


over  $200,000,000  to  complete.  A  supply  of  almost  one 
billion  gallons  of  water  daily  has  been  obtained.  The 
present  available  supply  should  be  sufficient  for  a  city 
of  8,000,000  inhabitants,  allowing  125  gallons  a  day  for 
each  person. 

Pressure  necessary.  —  In  the  case  of  the  water  supply 
of  Los  Angeles,  where  the  water  comes  in  a  main  nearly 
250  miles  from  the  Sierra  Nevada,  the  pressure,  or  head 
of  water,  as  it  is  called,  is  obtained  through  gravity.  When 
the  source  of  the  supply  is  many  feet  above  where  it  is  to 
be  delivered,  this  pressure  is  sufficient  to  cause  the  water 
to  flow  to  the  tops  of  the  highest  buildings.  Can  you  see 
why  ?  But  in  the  case  of  water  supplies  drawn  from  lakes 
or  rivers  near  at  hand  it  becomes  necessary  for  the  city 


Distribution  of  water  from  a  reservoir  or  a  stand  pipe. 

to  install  a  pumping  plant.  Water  is  pumped  into  a  res- 
ervoir or  standpipe  situated  on  an  elevation  above  the  city ; 
it  then  flows  by  gravity  through  the  pipes  of  the  city. 
Pressure  in  the  main  varies  as  the  height  of  the  source,  but 
also  with  the  length  and  diameter  of  the  main.  The  city 
must  provide  numerous  fire  hydrants  and  drinking  foun- 
tains, all  of  which  are  supplied  directly  from  the  city  .mains. 

Experiment.  —  To  illustrate  gravity  distribution  of  a  water  supply. 
Materials:  A  burette.     A  medium-sized  funnel.     Rubber  tubing. 
Method  and  Results:  Let  one  boy  hold  .the  funnel  and  another  the  burette 

(page  156).    Pour  water  into  funnel.    Why  does  water  run  into  the 

burette? 


156 


THE  COMMUNITY  WATER  SUPPLY 


If  air  in  the  rubber  tubes  hinders  the  flow  of  water,  squeeze  the 
tube  to  make  the  air  bubble  out.  Raise  and  lower  the  burette. 
To  what  height  will  the  water  rise? 

What  must  be  the  relation  of  the 
pipes  in  a  house  where  water  is  to  be 
used  to  the  reservoir? 

Protection  of  water  supplies.  — 

Where  a  city  obtains  its  water 
supply  either  from  the  source  of  a 
small  river  or  from  a  mountain 
lake,  it  becomes  necessary  to 
protect  the  watershed  or  surface 
of  the  land  down  which  water 
may  flow  into  this  river  or  lake. 
If  a  case  of  typhoid  should  occur 
in  a  house  on  such  an  area,  the 
germs  excreted  might  find  their 
way  into  the  river  or  lake,  es- 
pecially in  the  spring  when 
heavy  rains  occur.  Many  cases 
are  on  record  showing  how  lack 
of  proper  protection  for  the  water  supply  has  caused 
an  epidemic  of  typhoid. 

It  therefore  becomes  necessary  to  remove  when  pos- 
sible all  people  in  the  area  which  drains  into  a  water 
supply.  Where  this  is  impossible,  as  is  the  case  in  the  water 
shed  of  the  city  of  New  York,  there  must  be  strict  regu- 
lations to  prevent  pollution.  New  York  maintains  a  sani- 
tary police  force  which  sees  to  it  that  there  are  no  violations 
of  the  laws  which  protect  the  water.  Every  boy  or  girl  who 
wishes  to  be  a  good  citizen  should  remember,  when  camp- 
ing or  picnicking  near  any  public  water  supply,  that  the 
utmost  care  in  the  protection  of  the  water  should  be  used. 


HOW  TO  SCORE  MY  CITY  WATER  SUPPLY      157 

Why  this  chapter  was  written.  —  If  those  of  us  who  want 
to  become  future  voters  could  realize  our  obligations,  as 
well  as  the  benefits  which  are  given  us  by  our  communities, 
we  should  become  better  citizens.  What  are  some  of 
these  obligations  which  involve  the  care  of  public  water 
supplies  ? 

First.  We  should  never  injure  public  property.  Cost 
of  repairs  is  a  large  item  of  expense  in  the  keeping  up  of 
public  property  of  all  kinds,  and  this  is  equally  true  in  the 
upkeep  of  hydrants,,  water  pipes,  and  reservoirs. 

Second.  Care  of  public  watersheds  Damage  done  by 
careless  picnickers  may  be  much  greater  than  one  imagines. 
Always  clean  up  all  rubbish  and  decaying  material.  Use 
only  public  toilets  in  parks  or  near  watersheds. 

Third.  Report  to  the  health  authorities  the  breaking  of 
any  rules  of  sanitation  of  which  you  may  know. 

Fourth.  If  fishing  or  camping  is  done,  the  utmost  care 
must  be  observed  not  to  pollute  the  water. 

Fifth.  Care  in  the  use  of  water  at  home.  Leaks  should 
be  reported  at  once  and  stopped.  Leaking  faucets  are  a 
source  of  very  great  expense  to  the  city  and  often  to  the 
private  owner,  where  the  water  is  metered.  Water  should 
be  used  carefully  during  the  dry  seasons,  as  we  cannot 
afford  to  be  selfish  in  the  use  of  any  public  commodity. 

Sixth.  Personal  hygiene.  Avoid  drinking  water  that 
you  do  not  know  about.  Boil  all  water  before  drinking  if 
it  is  suspicious.  Learn  the  source  of  your  own  water 
supply,  its  strong  and  its  weak  points.  Especially  beware 
of  drinking  from  open  wells  in  visits  to  the  country. 

How  to  score  my  own  city  water  supply.  —  For  this  pur- 
pose direct  inquiry  from  the  city  department  of  water  supply 
may  result  in  obtaining  first-hand  information  and  pam- 


158 


THE   COMMUNITY  WATER  SUPPLY 


phlets  which  will  give  you  the  desired  information.  Visit 
the  city  reservoirs  and  filter  beds ;  the  city  pumping  sta- 
tion, if  you  have  one,  and  best  of  all,  if  possible,  the  source 
of  your  community  water  supply.  In  making  out  the  score 
card  which  follows  observe  these  directions. 


SCORE  CARD.     COMMUNITY  WATER  SUPPLY 


PER- 
FECT 
SCORE 

MY 

SCORE 

SOURCE 

Water  from  pure  source,  well  protected,  public  ex- 
cluded (20) 
Water  from  river  or  small  lake,  where  public  is  al- 
lowed, but  where  no  sewers  empty  (10) 
Water  from  bodies  of  water  in  which  sewers  empty 
(3) 

20 

SAFE   WATER 

No  epidemics  were  ever  traced  to  the  water  (10) 
Diseases  have  on  rare  occasions  been  traced  to  the 
water  (5) 
Diseases  frequently  traced  to  water  (o) 

10 

SAFEGUARDS 

Water  is  tested  frequently  and  is  filtered  or  chemi- 
cally treated,  and  filter  cleaned  regularly  do) 
Water  is  rarely  tested  but  is  filtered  (5) 
Water  is  rarely  tested  and  is  not  filtered  (o) 

IO 

DESIRABLE 
WATER 

Water  is  soft,  odorless,  tasteless,  colorless  (20) 
Water  is  hard  (10) 
Water  is  hard,  and  has  color,  taste,  or  odor  (3) 

20 

ADEQUATE 
SUPPLY 

Water  under  good  "head"  at  all  times  and  no  re- 
strictions imposed  on  its  use  in  dry  season  (20) 
Good  pressure  but  use  restricted  during  drought  do) 
Low  pressure  at  times  and  restricted  use  (3) 

2O 

PUBLIC 
CONVENIENCE 

City   maintains   public    fountains,    wading    ponds, 
drinking  troughs  for  animals,  and  bubble  fountains 
for  people  (10),  three  of  these  (5),  none  (o) 

10 

COST 

Rate  where  unmetered  not  over  $10.00  a  year  for 
family  of  five,  or  cost  where  metered  not  average 
over  $10.00  a  year  for  family  of  five  (10),  not  over 
$14.00  (5),  over  $14.00  (o) 

JO 

TOTAL 

100 

REFERENCE   BOOKS  159 

REFERENCE  BOOKS 

Barber,  First  Course  in  General  Science.    Henry  Holt  and  Company. 

Broadhurst,   Home  and  Community  Hygiene.     (For  teachers.)     Lippincott. 

Brown,  Health  in  Home  and  Town.    D.  C   Heath  and  Company. 

Coleman,  The  People's  Health.     The  Macmil  an  Company. 

Farmers'  Bulletin  478,  How  to  Prevent  Typhoid  Fever.    U.  S.  Dept.  of  Agriculture. 

Godfrey,  The  Health  of  the  City.    Houghton  Mifflin  Company. 

Hazen,  Clean  Water  and  How  to  Get  It.     (For  teachers.)     John  Wiley  and  Sons. 

Hughes,  Community  Civics.     Allyn  and  Bacon. 

Hough  and  Sedgwick,  The  Human  Mechanism,  Part  II.     Ginn  and  Company. 

Mason,  Water  Supply.     (For  teachers.)     John  Wiley  and  Sons. 

O'Shea  and  Kellogg,  Health  and  Cleanliness.     The  Macmillan  Company. 

Smith  and  Jewett,  Introduction  to  the  Study  of  Science.     The  Macmillan  Company. 

Trafton,  Science  of  Home  and  Community.    The  Macmillan  Company. 


PART  IV.     HOW  THE    COMMUNITY 
CARES    FOR   ITS   CITIZENS 

CHAPTER  X 
ORGANIZATION  OF  A  CITY  GOVERNMENT 

Problems.  —  i.  To  learn  how  the  community  government 
is  organized,  how  new  regulations  are  made,  and  the  relation 
between  various  departments. 

2.  To  understand  the  reasons  for  placing  certain  supplies 
and  privileges  under  the  control  of  the  community. 

3.  To  learn  how  we  may  cooperate  with  the  community 
government. 

Project  I.  —  To  BECOME  FAMILIAR  WITH  THE  METHODS  OF  CON- 
TROL OF  PUBLIC  AFFAIRS  IN  MY  OWN  COMMUNITY. 

1.  Names  of  the  principal  public  officials,  their  offices,  duties, 
and  terms  of  office. 

2.  New  regulations  and  ordinances  passed  within  a  year.     Rea- 
sons for  these. 

3.  What  is  the  method  of  procedure  for  enacting  new  regulations? 

How  city  governments  came  to  be  organized.  —  A  com- 
munity is  a  group  of  people  who  live  together,  having 
more  or  less  the  same  interests  and  who  are  governed  by 
common  laws.  In  the  early  growth  a  community  may 
consist  of  very  few  people  and  these  people  may  live  so 
far  apart  that  carelessness  on  the  part  of  one  family  would 
not  endanger  the  health  or  rights  of  another.  But  when 
people  live  near  one  another  in  larger  communities  common 

160 


SUPPLIES  UNDER  CONTROL  OF  COMMUNITY       161 

needs  come  into  existence,  and  then  certain  rights  of  differ- 
ent members  of  the  community  must  be  respected.  For 
example,  people  own  buildings  or  land  or  farming  utensils 
or  some  other  things  which  they  have  bought  or  earned, 
and  these  things  belong  to  them.  Other  people  must 
respect  this  right  and  must  neither  harm  property  nor 
attempt  to  carry  it  away.  Hence  certain  laws  or  restric- 
tions have  developed  in  the  community,  which  all  people 
agree  to  respect  and  obey.  But  suppose  that  one  member 
of  the  community  does  not  agree  to  do  this,  or  pretends 
to  agree  but  steals  his  neighbor's  goods.  Then  there  is  the 
need  in  that  community  for  some  means  of  making  that 
member  of  the  community  obey  the  common  laws.  For 
this  purpose  we  have  organized  certain  bodies  which  we 
call  the  courts.  We  have  organized  also,  first  voluntarily 
by  citizens  and  later  in  the  development  as  a  paid  depart- 
ment, a  police  force,  compelling  the  careless  man  to  obey 
the  laws  which  are  made  for  the  common  good. 

Common  supplies  placed  under  the  control  of  the  com- 
munity. —  As  the  community  grows  in  size,  it  becomes 
necessary  that  the  health  of  its  citizens  be  safeguarded  by 
the  control  of  all  supplies  that  are  used  in  common.  Water, 
for  example,  may  at  first  be  obtained  from  wells,  but  a 
growing  community  soon  needs  more  water  than  can  be 
drawn  from  wells.  Besides,  a  well  may  become  contami- 
nated with  sewage,  since  human  and  other  wastes  soak  into 
the  ground  and  may  get  into  the  water  used  by  the  citizens. 
It  then  becomes  necessary  either  to  dig  deep  wells  or  to 
get  water  from  some  other  pure  source.  The  milk  supply 
also  must  be  carefully  safeguarded  if  people  in  the  commu- 
nity are  to  remain  healthy.  The  sale  of  various  kinds  of  ma- 
terials, especially  foodstuffs,  must  be  carefully  supervised 

H.  W.  CIV.  SCI.  COMM.  —  II 


162      ORGANIZATION  OF  A  CITY  GOVERNMENT 

and  regulated,  for  upon  pure  food  and  water  depends  much 
of  the  health  of  the  community. 

The  organization  of  schools.  —  Very  early  in  the  life 
of  a  community,  we  find  some  one  qualified  to  teach  who 
brings  the  children  together  and  sets  up  a  tiny  school. 
In  small  places  in  the  country  we  see  such  schools  now- 


Many  old  tenement  buildings  lack  proper  fire  escapes  and  often  where  they  exist  they 
are  loaded  with  rubbish  contrary  to  city  regulations. 

adays  where  twenty  or  thirty  students  are  brought  under 
the  care  of  a  single  teacher.  But  as  the  community  grows 
larger,  we  have  a  graded  school  with  children  of  different 
ages  under  different  teachers.  Ultimately  the  schools  ex- 
pand until  the  older  ^  students  are  sent  to  high  schools  and 
perhaps  to  college.  In  our  large  communities  in  this  coun- 
try we  find  all  kinds  of  institutions  of  learning  which  furnish 
free  education  to  those  who  wish  it. 

Fire  protection.  —  Another  thing  that  people  living  to- 
gether must  protect  against  is  the  common  enemy,  fire. 


CITY   STREETS 


163 


When  Benjamin  Franklin  lived  in  Philadelphia  many  years 
ago,  the  entire  fire  department  consisted  of  three  pumping 
engines.  When  a  fire  broke  out,  all  the  citizens  who  were 
interested  in  fires  went  to  help,  but  with  no  organized  effort 
on  their  part  their  work  was  often  ineffectual.  As  late  as 
1870,  the  city  of  New  York  had  no  paid  firemen,  and  the  citi- 
zens entered  into  volunteer  work  to  help  put  out  fires.  To- 
day New  York  has  the  largest  and  perhaps  the  most  effi- 
cient fire  department  in  the  world,  with  nearly  10,000  men 


Modern  apartments  :   fire  laws  respected. 

and  over  500  pieces  of  apparatus.  Fire  protection  in  a 
community  is  also  obtained  by  means  of  proper  laws  re- 
stricting the  kinds  of  buildings  put  up,  the  nearness  of  such 
buildings  to  each  other,  their  construction  and  provision  for 
fire  escapes.  In  a  community  with  good  laws  which  are  prop- 
erly observed,  there  are  very  few  fire  traps,  but  in  one  large 
city  under  a  bad  administration  not  many  years  ago,  out  of 
over  300  tenement  houses  which  were  built  only  1 5  conformed 
to  the  laws  which  were  designed  to  make  them  safe  from  fire. 
City  streets.  —  At  the  present  time  most  communities 
in  our  country  have  well-lighted  streets  with  curbs  and 


164      ORGANIZATION  OF  A  CITY   GOVERNMENT 

gutters  to  prevent  flooding  of  the  sidewalks.  They  are 
also  provided  with  letter  boxes  and  other  conveniences. 
A  well- organized  community  also  takes  care  that  its 
streets  are  watered  and  swept  when  dirty,  that  garbage 
and  ashes  are  collected  and  properly  disposed  of,  and  that 
all  possible  care  is  taken  to  make  the  city  a  safe  place  to 
live  in.  The  people  enjoy  the  advantages  of  these  things, 
and  the  city  pays  the  bills. 

Public  recreation.  —  Nowadays  cities  and  towns  are 
coming  to  recognize  the  fact  that  adults  as  well  as  children 
need  a  place  to  play  in.  Not  only  does  the  ideal  com- 
munity furnish  parks  which  are  designed  to  be  beautiful  as 
well  as  healthful,  but  it  also  provides  playgrounds,  public 
baths,  community  meeting  places,  stadiums  in  which  games 
are  held  outdoors,  theaters,  and  many  other  opportunities 
for  recreation  and  amusement. 

The  work  of  the  department  of  health.  —  No  part  of  the 
organization  of  a  community  government  is  of  more  im- 
portance than  the  health  department.  Too  many  people 
are  careless,  and  others  are  selfish,  and  still  others  are 
not  well  informed,  so  that  diseases  which  are  catching  may 
be  spread  by  innocent  people  who  know  nothing  about 
such  diseases.  For  this  reason,  the  health  department  is  of 
much  importance  because  by  means  of  laws  it  can  quaran- 
tine or  isolate  people  who  have  contagious  diseases  which 
might  be  carried  to  others.  Moreover,  the  department 
of  health  is  expected  to  look  after  the  welfare  of  all  sick 
people  who  are  unable  to  pay  for  the  services  of  a  doctor. 
In  such  cities  as  New  York,  Chicago,  Cleveland,  Cincinnati, 
St.  Louis,  and  many  others  not  only  does  the  health  de- 
partment provide  many  hospitals  for  almost  every  kind  of 
disease,  but  the  city  also  provides  ambulances  in  which 


INSPECTION  OF  FOOD 


165 


to  carry  the  sick.  In  case  of  an  accident  on  the  city 
streets  or  in  a  building,  an  ambulance  takes  the  person  to 
a  city  hospital,  where  a  city  doctor  attends  him  and  nurses 
take  care  of  him.  These  doctors  and  nurses  are  paid  out 
of  the  city  budget.  The  community  also,  if  it  is  a  large 
one,  has  special  sanatoria  for  people  who  have  tuberculosis ; 
it  has  special  homes  for  the  feeble-minded,  for  the  insane, 


A  modern  hospital  ward. 

and  for  those  who  are  incurably  sick ;  and  it  provides  shel- 
ter for  the  needy. 

Inspection  of  food.  —  The  department  of  health  also 
inspects  the  conditions  under  which  food  is  manufactured 
and  sold.  Dairies,  for  example,  are  carefully  watched 
by  either  state  or  community  inspectors.  Regulations 
are  made  for  the  care  of  milk,  both  at  the  farm  where 
it  is  produced  and  on  the  cars  when  it  is  brought  to 
the  cities.  Milk  is  not  permitted  to  be  sold  in  open 
cans  in  most  cities,  for  in  this  way  germs  and  also  flies, 
which  bear  millions  of  germs  on  their  feet,  might  'get 


166       ORGANIZATION  OF  A   CITY   GOVERNMENT 

to  it  and  contaminate  it.  Canned  goods  are  carefully  in- 
spected at  the  factories  and  sometimes  at  the  places  of  sale. 
Many  goods  are  inspected  by  the  government,  and  most 
communities  have  laws  with  reference  to  the  sale  of  un- 
screened and  uncovered  vegetable  foods.  These  laws  are 

of  great  importance 
in  the  summer  when 
foods  may  easily  re- 
ceive harmful  germs 
from  dust.  The  sale 
of  decayed  foods  is 
prohibited  since  they 
might  harm  those 
who  use  them. 

Regulation  of  drugs 
and  patent  medicines. 
-  The  health  depart- 
ment also,  with  the 
aid  of  the  Federal 
Government,  super- 
vises the  sale  of  drugs 
and  patent  medicines. 
Habit-forming  drugs, 

Inspection  of  milk.  guch     ag     cocaine     or 

heroin,  are  not  allowed  to  be  sold  without  a  doctor's 
prescription.  There  are  patent  medicines  which  contain 
heart  depressants  or  other  dangerous  drugs;  these  must 
be  labeled  so  that  all  may  know  what  they  buy.  Drugs 
containing  alcohol  must  also  be  labeled  stating  the  amount 
of  alcohol. 

Care  of  school  children.  —  One  of  the  most  important 
pieces  of  work  of  the  department  of  health  is  the  care  of 


CARE  OF  SCHOOL  CHILDREN 


167 


school  children.  It  has  been  shown  that  the  death  rate 
in  receat  years  is  declining  in  the  cities,  while  in  the  country 
it  remains  about  stationary.  This  decline  is  due  to  the 
care  taken  of  young  babies  and  school  children  by  the  de- 
partments of  health  in  the  cities.  Not  only  do  most  well- 


An  ideal  arrangement  of  school  buildings.  The  four  groups  of  i,  2,  3,  4  are  elemen- 
tary schools  for  grades  1-6.  A,  B,  C,  and  D  are  junior  high  schools.  The  senior 
high  school  with  its  classical,  household  arts,  technical  and  commercial  departments 
is  shown  in  the  center.  Each  school  has  appropriate  playground.  This  illustrates 
a  city  area  of  4  square  miles.  (From  a  suggestion  by  Dr.  Snedden.) 

regulated  schools  have  a  school  physician  and  nurse,  but 
in  many  cities  they  have  in  addition  clinics  for  the  care  of 
the  eyes,  nose,  and  teeth,  in  which  pupils  may  have  this 
work  done  free  of  charge.  Many  large  communities  have 
established  out-of-door  schools  for  anemic  and  tubercular 
children.  In  other  cases,  kitchens  have  been  established 


i68      ORGANIZATION  OF  A  CITY   GOVERNMENT 

in  the  school  building,  where  hot,  nutritious  meals  are 
served  at  cost  for  those  who  can  afford  to  pay,  and  free 
for  those  who  cannot.  These  and  many  other  things  of 
a  similar  nature  are  done  by  the  departments  of  health, 
in  cooperation  with  school  boards,  in  progressive  com- 
munities. 

Under  ideal  conditions  a  city  will  have  many  small 
schools  for  pupils  up  to  twelve  years  of  age,  located  near 
the  homes  of  the  children.  Junior  high  schools  should  be 
located  at  central  points,  to  which  pupils  may  walk  from  a 
distance  of  a  mile  or  more.  One  large  central  senior  high 
school  will  take  pupils  from  several  junior  schools.  What 
advantages  of  the  grouping  of  the  schools  as  shown  in  the 
illustration  on  page  167  can  you  name? 

How  we  may  cooperate  with  a  city  government.  —  We 
have  seen  that  a  city  government  is  doing  much  for  us. 
We  are  supplied  with  clear,  pure  water  in  sufficient 
quantity  for  cooking,  bathing,  and  drinking  at  a  small 
cost.  Our  milk  and  food  are  protected  from  germs.  The 
streets  are  cleaned ;  garbage  and  sewage  are  removed ;  and 
the  cost  is  included  either  directly  in  taxes  or  indirectly 
in  the  rent  we  pay.  We  have  free  schooling,  and  in  some 
cities  may  even  go  through  a  free  university  if  we  desire. 
And  above  all  these  things  our  health  as  well  as  our  neigh- 
bor's is  safeguarded.  Should  we  not,  therefore,  even 
though  we  are  not  actual  voters,  be  just  as  much  interested 
in  good  government  as  if  we  were  paying  the  taxes ;  for  after 
all  we  are  getting  more  out  of  the  community  than  does  the 
voter  who  actually  pays  the  money  into  the  city  treasury. 
Every  boy  and  girl  who  reads  these  lines  should  have  the 
interest  of  his  or  her  community  at  heart,  for  some  day  all 
may  become  adult  citizens  in  that  community.  We  should 


COOPERATION  WITH  A  CITY  GOVERNMENT     169 

do  all  in  our  power  to  help  the  officers  and  the  members  of 
the  board  of  health,  the  police  and  the  fire  department, 
and  our  teachers  as  well. 

REFERENCE  BOOKS 

Allen,  Civics  and  Health.     (For  teachers.)     Ginn  and  Company. 

Cabot,  et  al.,  A  Course  in  Citizenship.    Houghton  Mifflin  Company. 

City  of  New  York,  Municipal  Yearbook.     (For  teachers.) 

Dole,  Our  Young  Citizen.    D.  C.  Heath  and  Company. 

Dunn,  The  Community  and  the  Citizen.    D.  C.  Heath  and  Company. 

Finch.  Everyday  Civics.  American  Book  Company. 

Garber,  Course  of  Study  in  Civics,  Grades  VII  and  VIII.  For  the  Public  Schools 
of  Philadelphia.  Board  of  Public  Education. 

Guitteau,  Preparing  for  Citizenship.    Houghton  Mifflin  Company. 

Hughes,  Community  Civics.    Allyn  and  Bacon. 

McCarthy,  et  al.,  Elementary  Civics.     Thompson,  Brown  and  Company. 

Moore,  The  Youth  of  the  Nation.    The  Macmillan  Company. 

Nida,  City,  State  and  Nation.    The  Macmillan  Company. 

Rexford,  et  al.,  Articles  on  Community  Civics.    Outlook. 

Smith,  Our  Neighbor,  Good  Citizenship  in  Rural  Communities.  J.  C.  Winston 
Company. 

Wilcox,  Great  Cities  in  America,  their  Problems  and  their  Government.  (For  teachers.) 
The  Macmillan  Company. 

Willard,  City  Government  for  Young  People.    The  Macmillan  Company. 

Wood,  Sanitation  Practically  Applied.     (For  teachers.)     John  Wiley  and  Sons. 

Zueblin,  American  Municipal  Progress.  (For  teachers.)  The  Macmillan  Com- 
pany. 

Ziegler  and  Jaquette,  Our  Community.    J.  C.  Winston  Company. 


CHAPTER   XI 

HOW  THE  COMMUNITY  PROVIDES  FOR 
PURE  FOOD 

Problems.  —  i.  To  learn  the  steps  taken  by  government, 
state,  and  town  in  insuring  a  pure  food  supply. 

2.  To  learn  the  dangers  from  milk  and  how  to  avoid  them. 

3.  To  learn  the  advantages  and  dangers  of  cold  storage. 

4.  To  learn  the  essential  requirements  to  make  a  food  store 
sanitary. 

Experiments.  —  i.   To  discover  if  the  milk  we  buy  is  cleaa  or  dirty. 

2.  To  pasteurize  milk  and  learn  the  effect  on  its  keeping  quality. 

3.  To  discover  the  effect  of  a  freezing  temperature  upon  bacteria. 

Project  I.  —  To  INVESTIGATE  THE  SUBJECT  OF  PURE  FOODS  IN 

MY  OWN  COMMUNITY. 

1.  Health  officer  —  duties  —  how  equipped  for  his  work. 

2.  Regulations  —  government,  state,  and  local. 

3.  By  personal  inspection,  find  which  grocers,  bakers,  meat  and 
fish  dealers,  fruit  and  candy  shops  and  restaurants  best  meet  the 
pure  food  regulations. 

4.  Try  to  interest  your  friends  to  trade  with  those  dealers  whose 
food  is  best  protected  against  contamination. 

5.  Make  a  full  written  report  to  submit  to  your  teacher  or  to  pre- 
sent to  the  class. 

Did  you  ever  stop  to  think  how  the  foods  we  eat  are 
protected  and  made  safe  for  us  ?  Not  only  does  the  United 
States  Government  have  laws  which  deal  with  the  pro- 
tection of  foods,  but  most  state  governments  do  as  well. 
Both  have  a  staff  of  men  whose  business  it  is  to  go  from 

170 


MEANS  OF  PROTECTING  FOOD  SUPPLIES         171 

place  to  place  and  inspect  all  kinds  of  foods  which  are  used 
in  a  community  so  as  to  keep  them  safe  for  human  con- 
sumption. The  milk  you  drink  has  been  inspected  at  the 
farms  where  it  was  taken  from  the  cow.  It  was  packed 
in  ice  and  sent  in  refrigerator  cars  to  the  city,  where  in- 
spectors again  examined  it  to  see  that  it  was  not  contami- 
nated before  it  was  pasteurized  and  bottled  by  the  great 
milk  companies.  In  the  cities,  the  health  departments 
supervise  the  work  and  also  see  that  fish,  meats,  vege- 
tables, fruits,  and  other  easily  spoiled  foods  are  put  on 
sale  under  conditions  of  cleanliness  and  safety  to  human 
beings.  Meats  bear  the  mark  of  inspection,  by  federal 
officials.  Groceries  and' canned  goods  are  protected  from 
adulteration  by  pure 
food  laws.  All  pre- 
served goods  are 
labeled  so  that  each 
one  may  know  just 
what  preservatives 
are  used.  This  is 
done  so  that  no  poi- 
sonous materials  may 
be  put  into  the  pre- 
serving substances 
in  quantities  inju- 
rious to  health. 

Means  of  protect- 
ing food  supplies.  - 

_  Examining  and  weighing  milk  upon  its  receipt. 

It  was  not  so  long 

ago  that  communities  did  not  take  very  great  care  of  their 
food  supplies.  We  have  gradually  become  educated,  so 
that  now  most  communities  have  the  proper  facilities 


172     HOW  THE  COMMUNITY  PROVIDES  PURE  FOOD 

for  caring  for  foods  on  sale.  Some  communities,  however, 
are  not  so  careful,  and  although  laws  may  be  made  they 
are  not  kept.  Especially  is  this  true  of  smaller  places 
where  the  members  of  health  boards  or  other  officials  do 
not  see  the  need  for  close  supervision.  This  is  your  op- 
portunity to  do  your  duty  as  a  young  citizen.  Are  there 

farms  near  where  you 
live  that  produce 
dirty  milk  ?  Are 
there  stores  in  which 
milk  is  sold  in  cans 
unprotected  from 
flies  and  dirt?  Do 
you  do  your  part  at 
home  in  protecting 
your  milk  and  other 
foods  in  hot  weather  ? 

Experiment. —  To  discover 
if  the  milk  we  buy  is 
clean  or  dirty. 

Materials:  Funnel.     Ab- 
Bottling  milk  for  delivery.  sorbent  ^^    ^ 

Method:  Wet  the  cotton  with  water  and  place  it  in  the  funnel.  Filter  a 
quart  of  milk  through  it.  If  the  milk  is  clean,  there  will  be  no  black 
dirt  on  the  cotton. 

Are  your  food  supplies  bought  when  fresh  and  used 
when  fresh  ?  Do  you  read  the  labels  on  your  canned  goods 
and  preserves,  and  do  you  know  what  these  labels  mean? 
If  you  are  to  be  a  really  useful  member  of  your  community, 
you  should  not  only  know  the  pure  food  laws  and  their 
meaning,  but  also  you  should  do  your  part  in  making  it 
possible  to  carry  out  these  laws. 

What  is   pure   milk  ?  —  Most   of   us,   especially  when 


WHAT  IS  PURE  MILK?  173 

young,  use  a  good  deal  of  milk.  It  is  indeed  one  of  the  most 
important  of  human  foods,  but  also  one  of  the  most 
easily  contaminated.  We  know  that  milk  spoils  readily. 
We  know  also  that  the  souring  of  milk  is  caused  by  bac- 
teria. Milk,  even  when  it  comes  direct  from  the  cow,  con- 
tains some  bacteria.  In  order  to  grade  milk  according  to 
purity  certain  standards  have  been  agreed  upon  by  medi- 
cal associations  and  public  health  societies,  usually  fol- 
lowed in  most  places  where  good  milk  is  obtained.  They 
recognize  three  grades  of  milk.  The  first  is  Grade  A .  This 
milk  must  come  from  cows  which  are  free  from  all  disease 
and  which  are  examined  frequently  by  inspectors,  and 
when  the  milk  is  delivered  raw  (which  means  not  pas- 
teurized), it  must  have  not  more  than  10,000  bacteria  to 
the  cubic  centimeter.  To  have  such  a  condition  means 
that  the  barns  must  be  clean,  that  the  cows  must  be  clean 
at  the  time  of  milking,  that  the  workers  must  be  free 
from  dirt  and  disease,  and  that  the  dairy  and  its  cans  must 
be  in  spotless  condition.  Milk  such  as  has  just  been  de- 
scribed is  very  expensive  because  of  the  care  needed,  but 
it  is  the  purest  milk.  Grade  A  milk  which  is  pasteurized 
must  be  produced  from  cows  free  from  disease,  the  gen- 
eral sanitary  conditions  must  be  good,  and  the  bacterial 
count  must  not  be  over  200,000  before  pasteurization, 
and  not  more  than.  30,000  before  delivery  to  the  con- 
sumer. Grade  B  .milk,  which  is  the  kind  usually  bought 
in  most  large  cities,  when  sold  raw  must  contain  not  more 
than  300,000  bacteria  to  the  cubic  centimeter  and  when 
pasteurized  must  contain  not  more  than  1,000,000. to  the 
cubic  centimeter  before  pasteurization  and  not  more  than 
100,000  per  cubic  centimeter  at  the  time  of  delivery.  Any 
lower  grade  of  milk  than  this  should  be  used  only  for  cook- 


174     HOW  THE  COMMUNITY  PROVIDES  PURE  FOOD 

ing  purposes,  as  the  bacteria  are  too  numerous  to  allow  it 
to  be  used  in  other  ways  with  safety. 

Experiment.  —  To  pasteurize  milk  and  learn  the  effect  on  the  keeping  quality 
of  the  milk. 

Material:  Two  half-pint  milk  bottles.  A  pail  or  kettle  large  enough 
to  hold  one  of  the  bottles.  Thermometer. 

Method:  Fill  each  bottle  two-thirds  full  of  fresh  milk.  Close  the  bottles 
with  a  plug  of  absorbent  cotton.  Set  one  bottle  of  milk  on  a  strip  of 
wood  in  a  pail  or  kettle.  Add  a  pint  of  water  and  heat  gradually  to  160° 
F.  Keepat  this  temperature  20  minutes.  Remove  the  bottle  of  milk  ; 
cool  it  quickly  by  running  water  or  setting  it  in  cold  water.  Label 
the  two  bottles  of  milk  and  leave  them  side  by  side  in  a  warm  room 
for  two  days.  The  souring  of  milk  is  caused  by  bacteria.  The  sour- 
ness then  is  an  indication  of  the  amount  of  bacterial  action. 

Result  and  Conclusion:  After  two  days  carefully  remove  a  teaspoonful 
of  milk  from  each  bottle.  Test  sourness  by  taste.  What  effect  does 
pasteurization. have  on  the  growth  of  bacteria  in  milk? 

How  pure  milk  is  obtained.  —  In  order  to  have  pure 
milk  it  is  necessary  that  the  utmost  care  be  taken  from  the 
time  the  milk  reaches  the  milk  pail  until  the  time  it  is  de- 
livered to  the  user.  In  an  effort  to  have  the  farms  and 
cows  kept  in  the  best  of  condition,  a  score  card  (see 
page  175)  is  used  by  the  inspectors,  and  each  dairy  which 
falls  below  a  certain  grade  is  not  allowed  to  supply  milk 
until  it  brings  up  the  condition  of  the  cows  or  buildings  to 
the  required  score.  The  purest  milk  comes  from  cows  which 
are  healthy  and  kept  in  clean  cow  yards,  and  yet  one  dirty 
or  sick  milker  might  send  his  germs  in  the  milk  to  do  harm 
in  the  city  where  it  is  delivered.  Care  then  must  be  exer- 
cised at  every  point.  The  milk  must  be  cooled,  put  into 
clean  containers  and  kept  at  a  temperature  not  higher 
than  50  degrees  Fahrenheit  during  its  transit  from  the 
farm  to  the  city.  When  we  remember  that  the  city  of-  New 
York  gets  its  milk  supply  from  eight  states  and  Canada, 
and  that  some  of  its  milk  is  over  four  days  old  when  it 


HOW  PURE   MILK  IS  OBTAINED 
CITY   MILK   DEPOT   SCORE   CARD 


175 


EQUIPMENT 

SCORE 

METHODS 

SCORE 

2  5 

Clean  yard       

No  open  privies  within  500  ft.     .     . 
Locality  insanitary  —  deduct  2.  5 

2-5 
o 

Clean  utensils       
Clean  floor        

5 
i 

_  ^  a,       .  ,       ^ 

Clean  walls 

I 

Cellar  dairy                    

o 

Flies,  none  

5 

few           

o 

Floor,  cement  
tight  boards      

2.5 

I 

Utensils 
sterilized  in  autoclave     .... 

5 

dirt      
Walls  cemented  or  painted      .     .     . 
whitewashed      
papered    

o 
i-5 

i 
.5 

sterilized  by  steam     
sterilized  tank  hot  water     .     .     . 
scrubbed       
only  rinsed    

3 

2 

i-5 

.5 

Lighting  good  

i 

Milk  kept  covered          

2  5 

natural  or  electricity 

Ventilation  good  

5 

Kept  45°  F.  or  below     
AZ°  F  to  =;o° 

5 

broken      . 

i 

none          .          

o 

Machinery  : 
bottler  and  can  washer  .     .  ...  ;  . 
milk  cooler   

2 
(J 

above  70°      ....   deduct  10 
delivered  ice  cold  

O 

5 
2.5 

bottling  machine    

1.5 

capping  machine    

cold  storage  plant       .     .    /'  'i    < 
autoclave      

2-5 

5 

clean  dustless  clothes      .... 
hands  clean       

i 
5 

Water,  purity  known     
Wash  basin  provided     

2 

i  5 

no  spitting  on  floor     

2 

Individual  towels       .... 

Total  score  (maximum  50)      ... 

Full  credits  given,  or  none 

reaches  the  consumer,  we  can  see  the  need  not  only  for  ice 
in  order  to  prevent  the  growth  of  bacteria  but  also  for 
pasteurizing  the  milk  to  kill  the  bacteria  already  present. 
In  most  cities,  the  large  milk  companies  pasteurize  their 
milk  on  a  large  scale  by  passing  it  over  pipes  filled  with 
steam.  This  raises  the  milk  to  a  temperature  of  about 
1 78  degrees  Fahrenheit  for  less  than  a  minute.  This  method 
of  pasteurization  (the  flash  method)  is  not  as  good  as  the 


176    HOW  THE  COMMUNITY  PROVIDES  PURE  FOOD 

slower  method  of  heating  the  milk  to  145  degrees  for  thirty 
minutes,  but  it  kills,  at  least,  the  harmful  bacteria  in  the 
milk.  After  all,  dirty  milk  is  dirty,  and  no  amount  of  pas- 
teurization can  make  it  clean.  An  interesting  project 
would  be  for  you  to  inspect  a  plant  of  some  milk  com- 
pany and  score  it  from  the  score  card  which  is  shown  on 
page  175.  The  same  can  be  done  by  the  boy  or  girl  who 
lives  in  the  country  for  the  farm  which  produces  milk  in 
his  or  her  neighborhood. 

Milk-borne  diseases.  —  One  of  the  chief  reasons  for  ex- 
ercising great  care  in  the  production  of  milk  is  the  fact 


A  case  of  typhoid  exists  at  farm  A,  which  has  a  large  milk  route.  Farm  B  has  a  small 
milk  route  and  supplies  some  milk  to  A.  The  cans  from  B  are  washed  at  A  and 
returned  to  B.  Each  black  dot  represents  a  case  of  typhoid  caused  by  infected 
milk.  How  do  you  account  for  the  cases  along  B's  route? 


that  milk  frequently  carries  certain  diseases.  Typhoid, 
diphtheria,  scarlet  fever,  tuberculosis,  and  septic  sore 
throat  are  all  human  diseases  which  may  be  carried  in  milk, 
while  diarrhea,  dysentery,  whooping  cough,  and  measles 
are  probably  carried  in  this  way.  Although  the  germ 


SEASONAL  VARIATIONS  IN  DISEASES 


177 


which  causes  tuberculosis  in  cows  appears  not  to  be  the 
same  as  that  which  occurs  in  human  beings,  yet  over 
30%  of  tuberculosis  in  children  under  five  years  of  age  is 
of  the  kind  that  is  found  in  cows.  Children  seem  to  be 
more  susceptible  to  the  cow  tuberculosis  than  adults,  so 
this  makes  it  all  the  more  necessary  to  inspect  the  cows  for 
tuberculosis  and  to  prevent  the  use  of  infected  cows  in  the 
production  of  milk.  One  of  the  most  serious  diseases 
carried  by  milk  is  typhoid  fever,  and  many  epidemics  have 
been  traced  to  this  source.  A  recent  milk-borne  epidemic 
of  typhoid  in  the  city  of  New  York  had  over  400  cases. 
The  preceding  diagram  shows  how  typhoid  fever  germs  may 
be  brought  to  the  city  and  given  out  in  the  milk  supply. 

Seasonal  variations  in  diseases.  —  In  some  cities  where 
the  board  of  health  keeps  tf 
careful  records  we  find  "» 
that  certain  diseases;  such 
as  diarrhea,  are  much 
more  prevalent  in  the 
summer  than  in  the  win- 
ter. This  seems  to  be 
due,  in  part  at  least,  to 
the  fact  that  foods  do  not 
keep  as  well  in  warm 
weather  as  in  cold  be- 
cause warm  weather  aids 
the  growth  of  germs. 
Milk,  as  well  as  other 
food,  is  easily  spoiled  in 
warm  temperatures.  As 


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it 

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Pneumonia 
Dipthericc 
—  Oroccp 
Scarlet  fever 

•••-,. 

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'--,. 



-•-•" 

Average  number   of   deaths    per   month   for 
180.7  - 1916,   of   four  common   diseases  in 


milk  is  the  food  of  babies, 
they  are  often  attacked  with  intestinal  diseases  in  sum- 
mer. It  was  found  recently  in  New  York  that  in  two 

H.  W.  CIV.  SCI.  COMM.  —  12 


178    HOW  THE  COMMUNITY  PROVIDES  PURE  FOOD 

groups  of  babies,  one  of  which  was  fed  on  pasteurized  and 
the  other  on  raw  milk,  64%  of  those  fed  on  raw  milk 
were  ill  with  diarrhea  during  the  summer,  while  only  24% 
of  those  fed  on  pasteurized  milk  were  ill.  When  we  re- 
member that  flies  are  very  prevalent  in  the  summer  time, 
that  they  frequent  dirty  places,  and  that  they  might 
take  up  the  diarrhea  germs  and  carry  them  to  the  milk, 
we  believe  this  is  one  reason  for  the  seasonal  variation  in 
disease.  Typhoid  fever  is  another  disease  which  is  more 
prevalent  in  warm  than  in  cold  weather.  There  are  other 
diseases,  as  pneumonia,  diphtheria,  and  scarlet  fever,  which 
are  more  prevalent  in  the  winter. 

Experiment.  —  To   discover   the    effect   of   a   freezing   temperature   upon 
bacteria. 

Materials:  One  half -pint  milk  bottle.     Milk. 

Method:  Fill  the  bottle  half  full  of  fresh  sweet  milk.  Close  the  bottle 
with  a  wad  of  absorbent  cotton.  Place  this  out  of  doors  when  the 
temperature  is  considerably  below  freezing.  In  warm  weather  pack  it 
in  salt  and  ice.  Keep  it  below  the  freezing  point  for  4  hours.  Then 
leave  it  in  the  air  at  usual  room  temperature  for  two  days.  If  sour- 
ness develops,  bacteria  must  be  alive  in  it. 

Results  and  Conclusion:  After  two  days  test  for  sourness  by  taste.  Com- 
pare with  the  results  in  the  preceding  experiment.  Which  is  more 
effective  in  checking  growth  of  bacteria,  pasteurization  or  freezing? 

Cold  storage  and  its  relation  to  foods.  —  We  hear  a  good 
deal  nowadays  about  the  danger  of  cold  storage  foods. 
It  is  true  that  the  cold  storage  plants,  which  have  come 
to  be  almost  a  necessity  for  large  communities,  frequently 
keep  meats,  fish,  and  other  foods  for  periods  of  from  several 
weeks  to  several  months,  or  even  longer.  While  storing 
foods  in  ice  at  a  freezing  temperature  changes  their  flavor, 
yet  if  the  food  is  fresh  when  it  is  put  in  cold  storage  and  if 
it  is  used  soon  after  it  is  taken  from  cold  storage,  no  harm 


HOW    OUR    MEATS    ARE    PROTECTED 


179 


is  done.  Foods  kept  in  cold  storage  a  long  time  are  soft- 
ened so  that  bacteria  grow  rapidly  in  them.  Sometimes 
fish  or  meats  are  put  into  cold  storage  after  the  bacteria 
have  begun  to  spoil  them.  Such  foods  would  be  unfit  to 
eat  after  coming  from  cold  storage.  On  the  whole  cold 
storage  is  a  boon  to 
modern  society,  for 
it  enables  us  to  have 
fresh  vegetables,  eggs, 
and  other  perishable 
foods  at  times  when 
they  could  not  other- 
wise be  obtained. 

How  our  meats  are 
protected.  —  All  over 
the  United  States 
the  government  has 
placed  federal  inspec- 
tors whose  business 
it  is  to  see  that  all 
animals  killed  for 
meat  are  in  good  con- 
dition. These  inspec- 
tors work  in  the  great  slaughterhouses  and  packing  houses. 
Work  is  carried  on  in  over  244  cities  and  in  over  3000 
different  large  establishments.  Pork  is  examined  for  tri- 
china and  beef  for  tuberculosis,  while  the  buildings  in  which 
the  work  is  done  are  regulated  according  to  certain  sanitary 
standards.  The  clothes  of  the  workers,  the  appliances  for 
sterilizing  buckets,  knives,  tanks,  and  other  parts  of  the  plant, 
and  the  control  of  pests  are  all  regulated  by  law.  In  many 
cities  the  slaughterhouses  must  be  rat  proof,  screened 


Meat  kept  in  cold  storage. 


l8o     HOW  THE  COMMUNITY  PROVIDES  PURE  FOOD 


against  flies,  and  all  refuse  must  be  at  once  disposed  of. 
Is  there  a  slaughterhouse  in  your  town?  If  so,  are  the 
conditions  sanitary  there  ?  You  should  make  a  trip  to  this 
place  and  see  if  conditions  are  favorable,  and  then  report 
on  the  visit  as  a  home  project. 

The  sale  of  meats,  milk,  and  groceries.  —  One  of  the 
most  important  functions  of  your  board  of  health  is  to  see 
that  the  stores  in  which  milk,  meats,  fruits,  and  groceries 
are  sold  are  clean  and  sanitary.  In  many  communities 
the  law  provides  that  all  perishable  goods  must  be  kept 
under  glass  or  well  screened,  especially  in  the  summer 
season.  Can  you  see  a  reason  for  this?  Does  the  grocer 
with  whom  you  deal  have  a  clean  and  well-ventilated 
shop?  Are  the  receptacles  containing  flour,  sugar,  etc., 
always  kept  covered?  Are  vegetables  and  fruits  exposed 

CARE  OF  FOODS  IN  A  STORE 


KEPT  CLOSED 
UNDER  GLASS 

SHIELDED  FROM 
FLIES,  DUST, 
AND  HANDS 

IN  THE  RE- 
FRIGERATOR 

ELEVATED 
12  INCHES 
ABOVE  FLOOR 

MAY  BE  KEPT 
ON  FLOOR 

bread 

berries 

butter 

artichoke 

canned  goods 

cakes 

celery 

cottage  cheese 

cabbages 

carrots 

candy 

cherries 

dried  currants 

cantaloupe 

cucumbers 

cheese 

crackers 

eggs 

cauliflower 

nuts  (whole) 

opened  fruits 

dates 

fresh  fish 

cranberries 

onions 

pastry 

figs 

fresh  meats 

dried  fruits 

peas 

pies 

grapes 

milk 

dried  meats 

potatoes 

radishes 

lettuce 

mincemeat 

grapefruit 

pumpkins 

shelled  nuts 

peaches 

(fresh) 

lemons 

squash 

watermelon 

pears 

oysters 

oranges 

turnips 

(cut) 

prunes 

raisins 

plums 

watermelon 

pickled  food 

spinach 

so  that  people  may  handle  them  and  flies  and  other  ver- 
min touch  them?  If  so,  you  should  not  patronize  the 
place.  Food,  when  exposed  for  sale,  should  be  kept  cov- 
ered so  that  germs  cannot  get  to  it,  for  this  is  one  of 


THE  SALE  OF  MEATS,  MILK,  AND  GROCERIES      181 

the  easiest  ways  for  germs  to  be  spread.  Suppose  a  man 
with  tuberculosis  should  come  into  the  shop  and  cough  on 
the  fruits,  vegetables,  or  into  an  open  can  of  milk.  What 
would  prevent  you  from  innocently  carrying  home  those 
germs  and  taking  them  into  your  own  body?  An  ounce 
of  prevention  is  worth  several  pounds  of  cure  in  this  case. 
Let  us  all  work  together  to  make  our  community  a  safer 
place  as  a  result  of  reading  this  chapter. 

REFERENCE   BOOKS 

Abel,  The  Care  of  Food  in  the  Home.  Farmers'  Bulletin  375,  U.  S.  Dept.  of  Agri- 
culture. 

Bailey,  Sanitary  and  Applied  Chemistry.  (For  teachers.)  The  Macmillan  Com- 
pany. 

Broadhurst,  Home  and  Community  Hygiene.    J.  B.  Lippincott  Company. 

Browne,  Health  in  Home  and  Town.    D.  C.  Heath  and  Company. 

Bulletin  56,  Milk  and  Its  Relation  to  Public  Health.    U.  S.  Public  Health  Service. 

Hughes,  Community  Civics.    Allyn  and  Bacon. 

Jordan,  Food  Poisoning.     (For  teachers.)     University  of  Chicago  Press. 

Kinne  and  Cooley,  Food  and  Health.    The  Macmillan  Company. 

Newman,  Bacteria.     (For  teachers.)     G.  P.  Putnam's  Sons.     . 

Olsen,  Pure  Foods.     Ginn  and  Company. 

Overton,  General  Hygiene.     American  Book  Company. 

Richards,  The  Cost  of  Cleanliness.     (For  teachers.)     John  Wiley  and  Sons. 

Rosenau,  The  Milk  Question.     (For  teachers.)     Houghton  Mifflin  Company. 

Tappan,  Editor,  Wonders  of  Science.    Houghton  Mifflin  Company. 

Wiley,  Foods  and  Their  Adulteration.  (For  teachers.)  P.  Blakiston's  Son  and 
Company. 

Wing,  Milk  and  Its  Products.    The  Macmillan  Company. 

Wood,  Sanitation  Practically  Applied.    (For  teachers.)    John  Wiley  and  Sons. 

Ziegler  and  Jacquette,  Our  Community.    J.  C.  Winston  Company. 


CHAPTER   XII 

THE  "  PURE  FOOD  AND   DRUG  ACT "   AND  HOW 
IT   OPERATES 

Problems.  —  i.  To  learn  what  is  meant  by  the  "Pure 
Food  and  Drug  Act." 

2.  To  learn  what  constitutes  "  adulteration  of  food." 

3.  To  learn  what  the  most  common  forms  of  adulteration 
are. 

4.  To  understand  some  of  the  dangers  from  patent  medi- 
cines and  drugs. 

5.  To  learn  how  to  help  my  community  to  demand  pure 
foods  and  to  reduce  the  use  of  patent  medicines. 

Experiments.  —  i.  To  see  if  "  butter  "  used  at  home  is  real  butter, 
oleomargarine,  or  renovated  butter. 

2.  To  test  jelly,  jam,  or  ice  cream  for  glucose  and  starch. 

3.  To  test  cheap  candy  and  jam  for  artificial  coloring. 

4.  To  test  milk  for  formaldehyde. 

Project  I.  —  To  MAKE  A  COLLECTION  AND  STUDY  or  LABELS  ON 

PACKAGE  FOODS  AND  PATENT  MEDICINE. 

1.  Contents  of  food  packages  not  food. 

2.  Claims  made  for  medicines  and  drugs. 

3.  Deleterious  substances  in  medicines. 

4.  Preparations  which  are  probable  frauds. 

Project  II.  —  TEST  VARIOUS  FOODS  FOR  ADULTERANTS. 

Make  list  of  foods  with  the  most  likely  adulterant.  Look  up 
methods  of  testing  for  these  adulterants.  Make  the  tests  and  report 
all  results. 

What  is  the  "  Pure  Food  and  Drug  Act  "?  —  We  hear  a 
good  deal  nowadays  about  pure  food,  and  people  are  be- 

182 


WHAT  IS  THE  "PURE  FOOD  AND  DRUG  ACT"?   183 


coming  educated  to  the  necessity  of  having  food  neither 
contaminated  nor  adulterated.  Not  many  years  ago 
many  of  our  prepared  foods  were  adulterated.  Of 
many  samples  of  food  tested  before  the  year  1906,  40 
per  cent  of  one  lot  of  500  samples,  41  per  cent  of  an- 
other lot  of  500  samples,  and  60  per  cent  of  a  third 
lot  of  500  samples 
were  found  to  be 
adulterated.  This 
showed  to  the  Con- 
gress of  the  United 
States  the  need  of 
protecting  people 
against  the  adultera- 
tion of  foods,  and  so 
in  1906  the  Pure  Food 
and  Drug  Act  was 
passed.  We  found 
also  that  our  meats 
were  not  always  pro- 
tected in  the  killing 
and  carriage  to  the 
consumer.  Then,  too,  patent  medicines  were  labeled  in 
such  a  way  as  to  make  people  think  that  they  could  cure 
diseases  when  often  such  a  cure  was  impossible.  In  other 
words,  they  were  mislabeled  and  did  not  tell  what  sub- 
stances were  contained  in  the  medicine.  The  Pure  Food 
and  Drug  Act  has  caused  the  makers  of  patent  medicines 
at  least  to  label  these  medicines  so  that  we  may  know 
some  things  that  are  contained  in  them. 

While  misrepresentations  cannot  be  made  by  the  labels, 
the  law  has  no  control  over  newspaper  and  circular  adver- 


An  inspector  purchasing  a  sample  food  product  for 
testing. 


184  PURE  FOOD  AND  DRUG  ACT 

tising.  Compare  the  claims  made  in  advertising  with  those 
on  the  package  to  see  if  they  agree. 

What  is  adulterated  food?  —  This  act  first  of  all  defines 
what  adulteration  is.  It  says  that  adulteration  is  any- 
thing which  is  added  to  food  to  cheapen  it :  anything  mixed 
with  food  to  reduce  or  injure  its  quality;  any  valuable 
part  taken  away  from  the  food;  the  mixing  of  colored  or 
stained  material  with  food  to  conceal  damaged  or  in- 
ferior material;  the  addition  of  poisonous  materials  or 
the  use  of  any  decayed  animal  or  vegetable  substances 
unfit  to  eat.  Adulteration  then  is  a  very  large  term 
under  this  act,  which  also  provides  for  the  punishment  of 
any  one  who  is  detected  practicing  any  of  these  adultera- 
tions. 

How  the  Pure  Food  and  Drug  Act  operates.  —  Although 
Congress  doubtless  thought  it  had  made  good  legislation 
in  the  case  of  the  Pure  Food  and  Drug  Act,  the  results 
are  not  satisfactory  in  all  respects.  The  act  has  pre- 
vented the  adulteration  of  foods  where  the  civic  authorities 
are  active,  but  if  the  board  of  health  of  a  town  or  city  is 
not  alert,  foods  kept  in  bulk  may  be  adulterated  by 
dishonest  manufacturers  or  storekeepers.  The  act  does 
make  it  necessary  for  the  firm  putting  up  the  goods  in 
containers  to  tell  exactly  what  is  in  the  container.  For 
example,  if  your  grocer  keeps  cheap  jellies,  jams,  marma- 
lades, or  flavoring  substances,  you  may  find  labels  on  the 
bottles  or  cans  stating  that  artificial  coloring,  a  preserva- 
tive and  10%  glucose  are  used.  The  federal  Food  and 
Drug  Act  exercises  no  control  over  the  sale  of  foods  and 
medicines  prepared  in  one  state  and  sold  in  the  same  state. 
The  law  applies  only  to  interstate  commerce.  The  state 
laws  apply  to  preparations  manufactured  and  sold  in  the 


LACK  OF  KNOWLEDGE  185 

state  and  some  states  are  very  lax  in  this  matter.  What 
are  the  food  and  drug  laws  in  your  state?  Are  they  well 
enforced  ? 

Cheap  candies  are  often  adulterated  and  colored  with 
cheap  dyes.  They  are  frequently  sweetened  with  sac- 
charin and  contain  white  clay  or  glue  and  are  some- 
times covered  with  shellac  mixed  with  iron  rust  or  lamp- 
black. Different  fruit  flavors  are  made  synthetically  out 
of  coal-tar  products.  There  is  also  danger  from  soda 
fountains  where  saccharin  is  used  in  place  of  sugar  and 
many  fruit  flavorings  are  made  of  coal-tar  products.  In 
addition  to  this,  the  glasses  back  of  the  counter  in  the 
soda  fountains  are  often  not  well  washed  and  there  is 
much  danger  of  the  transfer  of  bacteria  from  one  person 
to  another  by  this  means.  We  should  patronize  only 
soda  fountains  which  use  individual  paraffin  paper  cups. 

Lack  of  knowledge  decreases  the  effectiveness  of  the 
Pure  Food  and  Drug  Act.  —  The  Pure  Food  and  Drug  Act 
permits  the  use  of  certain  adulterants  of  foods  and  drugs 
provided  the  adulterant  are  plainly  named  on  the  label 
of  the  container.  But  the  majority  of  people  are  not 
educated  in  these  matters  so  that  they  know  what  is 
harmful  and  what  is  harmless.  The  only  way  for  us  to 
know  how  properly  to  make  use  of  the  Pure  Food  and 
Drug  Act  is  to  get  some  reliable  information  as  to  what 
constitutes  harmful  preservatives  and  also  what  materials 
are  harmful  in  medicines.  Then  if  we  take  the  trouble  to 
read  the  labels  which  the  Pure  Food  and  Drug  Act  causes 
to  be  placed  on  the  containers,  we  can  sometimes  avoid 
taking  poisons  into  the  body.  There  are,  however,  many 
drugs,  some  of  which  are  poisons,  which  may  be  used  in 
" patent  medicines"  without  being  named  on  the  label. 


i86  PURE  FOOD  AND  DRUG  ACT 

Experiment.  —  To  see  if  the  "  butter  "  used  at  home  is  real  butter,  oleo- 
margarine, or  renovated  butter. 

Materials:  "  Butter  "  to  be  tested.  An  iron  tablespoon.  Test  tube. 
Toothpick.  Glass  rod.  Ice.  Fresh  milk. 

Method:  Heat  a  small  piece  of  the  sample  in  the  spoon,  stirring  with  a 
wood  toothpick.  Real  butter  boils  quietly  but  foams  freely.  Both 
oleomargarine  and  renovated  butter  boil  noisily  and  with  little  or 
no  foam. 

Add  a  teaspoonful  of  the  sample  to  test  tube  half-full  of  fresh  milk. 
Heat  and  stir  until  the  fat  is  liquid.  Surround  the  test  tube  with 
crushed  ice  or  ice  water  and  stir  with  the  glass  rod.  If  the  sample 
is  real  or  renovated  butter  it  will  make  many  separate  solid  grains 
throughout  the  milk  ;  if  oleomargarine,  it  will  solidify  in  one  hard 
lump. 

Result:  What  is  the  result  of  these  tests? 

Some  common  adulterations.  —  Many  adulterations  are 
met  with  every  day  and  are  not  at  all  harmful.  Oleomar- 
garine with  coloring  matter  in  it  is  sometimes  unlawfully 
sold  as  butter.  As  a  matter  of  fact,  oleomargarine  is 
perfectly  wholesome,  as  are  also  nut  butter,  nut  oils,  cotton- 
seed oil,  and  other  substitutes  for  butter.  Cottonseed  oil  is 
frequently  an  adulterant  or  substitute  for  the  much  more 
expensive  olive  oil.  Molasses,  honey,  and  maple  sirup  are 
often  adulterated  with  glucose  or  corn  sirup.  Corn  sirup 
is  a  good  enough  food,  but  it  is  cheaper  than  the  materials 
for  which  it  is  substituted  and  is  therefore  an  adulterant. 
Cheap  grades  of  condensed  milk  may  have  sugar  added  to 
them  to  take  the  place  of  foods  which  were  removed  from 
the  milk.  Coffee,  tea,  and  cocoa  are  frequently  adulterated 
by  the  addition  of  such  materials  as  cornstarch,  old  tea 
leaves,  chicory,  cocoa  shells,  and  other  cheap  products. 
Some  foods  may  have  adulterants  of  a  harmful  nature.  We 
have  spoken  of  candy  having  saccharin,  clay,  glue,  and  other 
materials  added  to  it.  We  also  have  chemicals  used  to 
change  the  color  of  meats,  such  as  saltpeter,  which  brings 


SOME  HARMFUL  PRESERVATIVES  187 

back  the  red  color  to  partly  decayed  meat,  and  in  the 
case  of  flour,  alum  and  other  poisonous  compounds  may 
be  retained  by  the  flour. 

Chicory  can  easily  be  detected  in  coffee  by  simply  adding 
the  ground  material  slowly  to  a  glass  of  water.  Chicory 
sinks  at  once.  Starch  in  coffee  can  easily  be  found  through 
the  iodine  test.  Saccharin  is  soluble  in  chloroform,  while 
sugar  is  not.  Glucose  added  to  honey  can  be  detected  by 
the  addition  of  a  few  drops  of  a  weak  solution  of  potassium 
iodide.  If  the  color  disappears  from  the  honey,  glucose 
was  present. 

Experiment.  —  To  test  jelly,  jam,  or  ice  cream  for  glucose  and  starch. 

Materials:  Samples  to  be  tested.  Test  tubes.  Fehling's  solution.1 
Iodine  solution.  Funnel  and  filter  paper. 

Method:  Add  a  teaspoonful  of  the  sample  to  a  test  tube  half  full  of  water 
and  heat.     Filter.    To  one-half  the  nitrate  add  5  c.c.  Fehling's  solu- 
tion and  boil.    A  red  precipitate  indicates  the  presence  of  glucose. 
To  the  remainder  of  the  filtrate  add  a  drop  or  two  of  iodine  solution. 
A  blue  or  blue  black  color  indicates  starch. 

Result:  Do  any  of  the  foods  tested  contain  glucose  or  starch? 

Experiment.  —  To  test  cheap  candies  and  jam  for  artificial  coloring. 

Materials:  Brightly  colored  candies,  cheap  jams,  evaporating  dish,  white 
woolen  yarn. 

Method:  Mix  a  tablespoonful  of  jam  or  a  piece  of  colored  candy  in  an 
evaporating  dish  half  full  of  boiling  water.  Put  into  this  a  piece  of 
white  woolen  yarn  and  boil  for  ten  minutes.  Then  remove  and  wash 
the  yarn  in  hot  water.  A  bright  color  left  on  the  yarn  indicates  arti- 
ficial dyes. 

Result:  What  substances  tested  were  colored  with  artificial  dyes? 

Some  harmful  preservatives.  —  But  more  harmful  in 
some  respects  is  the  use  of  preservatives.  Food  preserved 
by  means  of  heat  or  cold  is  good  food,  but  if  we  add 
chemical  substances  to  it  in  order  to  prevent  bacteria  al- 

1  Fehling's  solution,  made  by  dissolving  6.2  gm.  copper  sulphate,  3.5  gm.  Ro- 
chelle  salts,  and  2  gm.  potassium  hydroxide  in  100  c.c.  of  water. 


i88  PURE  FOOD  AND  DRUG  ACT 

ready  in  it  from  causing  further  decay,  tiien  such  preserva- 
tives become  harmful.  Many  foods  contain,  under  the 
Pure  Food  and  Drug  Act,  small  quantities  oi  alum,  borax, 
benzoate  of  soda,  benzoic  acid,  and  certain  sulphites. 
These  quantities  used  are  probably  harmless  to  any  one 
taking  a  small  quantity  of  the  substance  in  question,  yet 
they  are  not  substances  we  wish  to  have  added  to  food,  as 
they  may  indicate  that  such  foods  may  have  been  close  to 
the  point  of  decay  when  they  were  put  into  the  cans  or 
bottles. 

Experiment.  —  To  test  milk  for  formaldehyde, 

Materials:    Evaporating  dish.     Concentrated  hydrochloric  acid.     Ferric 

chloride  mixture  made  by  adding  2  c.c.  of  10%  ferric  chloride  solution 

to  i  liter  of  hydrochloric  acid. 
Method:  Mix  10  c.c.  milk  with  10  c.c.  of  the  acid-ferric  chloride  solution 

in  the  evaporating  dish.     Heat  slowly  to  boiling,  stirring  occasionally. 

A  violet  color  results  if  formaldehyde  is  present. 
Result:  What  is  the  result  of  your  test? 

Patent  medicines  and  the  Pure  Food  and  Drug  Act.  - 
The  American  people  are  probably  the  greatest  consumers 
of  "  patent  medicines  "  of  any  people  in  the  world,  but  we 
are  gradually  becoming  educated  through  the  working  of  the 
Pure  Food  and  Drug  Act  to  realize  that  many  patent  medi- 
cines are  harmful  rather  than  beneficial.  Medicines  should 
seldom  be  taken  except  under  the  advice  of  a  physician, 
for  the  human  body  is  usually  capable  of  curing  itself 
when  it  is  out  of  order.  The  chief  advantage  of  the  act 
with  reference  to  patent  medicines  lies  in  the  fact  that  the 
labels  on  the  bottles  must  not  tell  untruths,  as  they 
have  done  frequently  in  the  past,  because  the  act  prohibits 
fraudulent  statements  on  the  package  or  bottle.  When  a 
medicine  is  advertised  to  cure  everything,  it  is  evident  that 


DRUGS  AND  THEIR  DANGERS  189 

it  is  a  fraud.  Such  labels  have  been  changed  to  substitute 
the  word  "  remedy  "  for  the  word  "  cure." 

There  are  eleven  drugs  which  must  be  declared  on  the 
label  if  present  in  the  medicine.  They  are :  alcohol,  mor- 
phine, opium,  cocaine,  heroin,  alpha  and  beta-eucaine, 
chloroform,  cannabis  indica,  chloral  hydrate,  and  acetanilid. 
Other  drugs,  even  poisons,  like  arsenic  and  strychnin,  need 
not  be  disclosed  under  the  present  law. 

Drugs  and  their  dangers.  —  Patent  medicines  might  be 
divided  into  several  groups,  according  to  their  composition 
and  uses.  The  most  dangerous  of  them  contain  habit-form- 
ing drugs,  of  which  we  shall  speak  in  a  moment.  Another 
type  of  patent  medicine  includes  the  so-called  cough  sirups 
which  are  used  to  soothe  the  suffering  of  people  who 
have  tuberculosis.  Still  another  type  of  drug  is  said  to 
cure  people  who  have  incurable  diseases.  Such  drugs  are 
usually  sold  to  people  in  the  last  stages  of  disease,  and 
most  frequently  these  people  are  harmed  instead  of  helped. 
Drugs  are  dangerous  to  use  except  in  the  hands  of  expert 
physicians.  Last  of  all  are  the  medical  fakes,  "  cures  "  to 
make  thin  people  fat  and  fat  people  thin,  instruments 
to  cure  deafness,  or  to  bring  about  vitality  to  weak 
people. 

Most  headache  cures  are  harmful  and  even  dangerous. 
They  usually  contain  phenacetin,  acetanilid,  chloral,  mor- 
phine, or  some  other  drug  which  depresses  the  heart, 
causing  it  to  beat  more  slowly.  They  also  deaden  the 
sensation  of  pain.  Such  drugs  do  not  cure  headaches,  and 
their  use  simply  covers  up  the  real  cause  of  the  trouble 
and  makes  the  user  addicted  to  the  drug.  Moreover, 
if  a,  person  has  a  weak  heart,  these  drugs  may  slow 
down  its  action  until  death  follows  No  one  should 


PURE  FOOD  AND  DRUG  ACT 

use  headache  powders  without  first  knowing  what  they  con- 
tain nor  should  they  be  used  except  by  advice  of  a  phy- 
sician so  as  to  be  sure  they  do  not  contain  habit-forming 
drugs  or  poisons. 

Habit-forming  drugs.  —  The  basis  of  many  patent  medi- 
cines used  as  home  remedies  is  alcohol.  Some  of  these 
contain  over  50  per  cent  of  alcohol.  In  some  parts 
of  the  country  people  have  become  drunk  on  patent  medi- 
cines when  they  could  not  obtain  liquor.  Too  often  such 
medicines  have  been  the  cause  of  the  formation  of  a  habit 
of  taking  alcohol.  The  person  taking  the  drug  containing 
alcohol  feels  better  temporarily  because  of  the  deadening 
effect  of  the  alcohol  and  wants  more  of  the  same  drug. 
As  a  result,  he  soon  becomes  addicted  to  the  alcohol 
habit.  Other  habit-forming  drugs  contain  opium,  mor- 
phine, or  heroin.  The  users  of  these  soon  become  dope 
fiends. 

Medical  fakes.  —  Under  such  a  heading  would  be  placed 
the  so-called  cure-alls  for  incurable  diseases,  such  as  cancer 
cures,  consumptive  cures,  the  obesity  cures,  the  cures  for 
deafness  and  epilepsy,  and  many  others.  Many  of  these 
are  pure  and  simple  fakes.  Cures  for  over-fatness,  for 
example,  have  been  found  to  be  made  of  such  materials  as 
cream  of  tartar  and  baking  soda,  sweetened  and  colored 
pink.  It  is  perfectly  plain  that  such  materials  would  not 
make  a  fat  person  thin.  Tuberculosis  can  be  cured  only 
by  treatment  and  not  by  drugs.  Cancer  is  curable  only  in 
its  early  stages  and  so  far  as  known  not  by  drugs  at  all. 
Some  pieces  of  apparatus  sold  to  make  deaf  people  hear  are 
absolutely  valueless,  and  if  used  may  harm  the  middle 
ear. 

How  to  make  this  chapter  benefit  us.  —  We  have  already 


HOW  TO  MAKE  THIS  CHAPTER  BENEFIT  US     191 

said  that  the  chief  reason  why  the  Pure  Food  and  Drug 
Act  is  ineffective  is  because  people  do  not  have  sufficient 
knowledge  to  understand  it.  Those  of  us  who  have  been 
fortunate  enough  to  learn  something  of  its  applications 
can  easily  learn  more  by  working  up  a  project  on  some  in- 
teresting phase  of  this  chapter.  The  American  Medical 
Association  has  published  many  pamphlets  on  medical 
frauds  which  will  suggest  material  for  several  interesting 
reports  before  the  class.  Visit  your  home  grocery  store 
and  make  a  list  of  all  the  foods  with  labels  which  show 
that  harmful  preservatives  are  used.  Visit  some  good- 
natured  druggist  and  note  what  medicines  have  recorded 
on  the  labels  any  of  the  eleven  drugs  mentioned  on  page 
189.  Learn  if  you  can,  from  your  druggist  or  physician, 
other  prepared  medicines  which  contain  harmful  or  poison- 
ous drugs  not  indicated  by  the  label.  Collect  newspaper 
advertisements  of  medicines  and  compare  the  claims  made 
in  these  advertisements  with  those  on  the  labels.  Above 
all,  talk  over  the  subject  of  adulterants  and  patent  med- 
icines with  your  fathers  and  mothers  and  with  other  people 
who  you  think  might  be  interested. 

It  is  only  by  enlightening  many  people  that  we  can 
finally  make  public  sentiment  which  will  result  in  making 
new  laws  which  will  better  protect  the  people  of  this 
country  against  harmful  preservatives  and  still  more  harm- 
ful patent  medicines.  And  finally,  after  you  have  the  facts, 
score  up  your  community,  or  at  least  that  part  in  which 
you  live,  with  reference  to  the  points  suggested  in  the 
score  card  on  the  community  care  of  food  which  is  printed 
on  the  following  page. 


192 


PURE  FOOD  AND  DRUG  ACT 


SCORE  CARD.    COMMUNITY  CARE  OF  FOOD 


TOTAL 
SCORE 

MY 
SCORE 

MILK 
INSPECTION 

Milk  inspected  at  farm  where  produced  (2) 
Milk  inspected  in  transit  to  city  (2) 
Milk  inspected  in  bottling  establishment  (2) 
Milk  inspected  at  point  of  sale  (2) 
Tubercular  tested  cows  furnish  all  of  supply  (8) 
Laws  with  reference  to  typhoid  carriers  enforced  (5) 
Grading  of  milk  sold  based  on  standard  of  American 
Medical   Association    (see   p.    175)    and   sold   as 
graded;  all  milk  below  grade  "A"  pasteurized;  no 
dipped  milk  sold  (9) 

3° 

FOOD 
INSPECTION 

Regular  inspection  of  slaughterhouses  and  meats  (5  ) 
Regular  inspection  of  cold  storage  plants  (2  ) 
No  cold  storage  goods  unfit  for  public  use  sold  (3) 
All  bakeries  regularly  inspected  (3) 
Modern  baking  plant  in  community  (i) 
Foods  in  store  kept  according  to  schedule,  p.  180  (3) 
All  foods  on  push-carts  covered  (3) 
Butcher  shops  inspected    regularly   and    free  from 
flies  and  offal  (5) 
Shellfish  and  fish  supplies  safeguarded  and  inspected 

(s) 

All  persons  handling  foods  free  from  disease,  restau- 
rants clean  and  inviting  (5) 
Soda  fountains,   individual   and    sanitary  drinking 
cups  (5) 
Regular  inspection  of  weights  and  measures  (5) 

45 

PURE  FOOD 
AND  DRUG  ACT 

No  adulterated  candy  sold  (5),  some  (2),  much  (o) 
No  medical  fakes  sold  (10),  some  (4),  many  (o) 
No  headache  cures  sold  without  prescription   (10), 
some  (4),  many  (o) 

25 

TOTAL 

IOO 

REFERENCE  BOOKS 

Adams,  The  Great  American  Fraud.    American  Medical  Ass'n,  Chicago. 

Allen,  Civics  and  Health.     (For  teachers.)  -  Ginn  and  Company. 

Broadhurst,  Home  and  Community  Hygiene.     J.  B.  Lippincott  Company. 

Cramp,  The  Nostrum  and  the  Public  Health.    General  Science  Quarterly,  May,  1921. 

Fisher  and  Fish,  How  to  Live.     Funk  and  Wagnalls  Company. 

Forbes,  What  Not  to  Do  for  a  Headache.    World's  Work,  June,  1910. 

Gruenberg,  Elementary  Biology.     Ginn  and  Company. 

Hodgdon,  Elementary  General  Science.     Hinds,  Hayden,  and  Eldredge. 

Johnson,  The  Drug  Clerk  a  Poor  Doctor.     World's  Work,  July,  1910. 

Kebler,  et  al.,   Harmfulness  of  Headache  Mixtures.     Farmers'  Bulletin  377. 

Medical  Fakes  and  Fakers.     American  Medical  Ass'n,  Chicago. 

Nostrums  and  Quackery.     American  Medical  Ass'n,  Chicago. 

Olson,  Pure  Foods.     Ginn  and  Company. 

Overton,  General  Hygiene.     American  Book  Company. 

Russell,  The  Danger  in  the  Drug  Store.     Pearson's  Magazine,  June,  1910. 

U.  S.  Food  Administration,  Food  and  the  War. 

Wood,  Sanitation  Practically  Applied.    (For  teachers.)    John  Wiley  and  Sons. 


CHAPTER  XIII 

HOW   DISEASES   ARE   SPREAD   AND   HOW 
TO   FIGHT  THEM 

Problems.  —  i.    To  understand  the  dangers  from  common 
contagious  diseases. 

2.  To  learn  how  we  may  fight  contagious  diseases. 

3.  To  understand  the  relation  between  diseases  and  germs. 

4.  To  understand  how  to  obtain  immunity  against  cer- 
tain diseases. 

Experiments. —  i.   To  discover  the  distance  germs  may  be  scattered 
by  the  "  droplet  method  of  infection." 

2.   To  see  if  fumigating  with  formaldehyde  will  kill  bacteria. 

Project  I.  —  To  INVESTIGATE  THE  SPREAD  OF  DISEASE  IN  YOUR 

NEIGHBORHOOD. 

(Cover  a  period  of  at  least  3  months.) 

1.  What  diseases  —  (i)  contagious;   (2)  not  contagious. 

2.  Observe   habits  which  help  to  spread  disease  —  whether  the 
persons  are  at  the  time  suffering  from  disease  or  not.      List  them. 

3.  Observe  habits  which  help  check  the  spread  of  disease.    List 
them. 

Quarantine.  —  You  have  probably  all  seen  a  blasting 
gang  at  work.  You  have  noticed  just  before  the  blast  is 
sent  off  that  one  or  two  of  the  members  of  the  gang  go 
out  into  the  street,  waving  red  flags  and  calling  out 
loudly,  "  Fire  !  Fire  !  "  You  have  all  been  interested  to 
see  what  happens,  how  the  men  set  off  the  blast  with 
electricity,  how  the  whole  mass  rises  into  the  air  with  per- 
haps a  few  rocks  or  logs  flying  quite  high,  then  the  work- 
H.  w.  crv.  sci.  COMM.  —  13  193 


194 


HOW  DISEASES   ARE   SPREAD 


men  troop  back  to  the  place  where  they  were  drilling; 
work  goes  on  as  before  and  traffic  on  that  street  is  again 
resumed.  By  means  of  a  red  or  other  conspicuous  placard 
the  health  department  in  the  community  in  which  we  live 
warns  people  who  pass  of  the  fact  that  there  is  a  contagious 
disease  in  a  particular  house.  The  health  officer  in  a 
community  has  a  right  to  keep  people  in  who  are  sick 
with  certain  catching  or  contagious  diseases,  and  to  put  a 
placard  on  the  house,  that  all  may  know  of  the  danger  from 


ill 

BOARD  OF 
HEALTH 


Two  kinds  of  warnings  which  are  to  save  lives. 

disease  there      Restriction  on  a  sick  person  or  one  sus- 
pected of  being  infected  is  known  as  quarantine. 

What  is  a  contagious  disease  ?  —  But  we  might  well 
ask  what  are  contagious  diseases.  The  word  means 
"  catching,"  and  such  diseases  are  said  to  be  catching  dis- 
eases. We  know  some  of  them  very  well :  whooping  cough, 
measles,  diphtheria,  sore  throat,  and  common  colds.  Prac- 
tically all  such  diseases  are  communicated  to  others  in  much 
the  same  way  and  by  the  same  means.  Little  bacteria  or 
germs  which  cause  the  diseases  find  an  excellent  place  to 
grow  in  the  soft  mucous  lining  of  the  throat  and  nose. 


SOME   WAYS  CONTAGIOUS  DISEASES  ARE  SPREAD   195 

The  germs  causing  many  children's  diseases  grow  in  just 
such  places  and  are  communicated  usually  in  one  way,  that 
is,  by  the  germs  from  the  mouth  or  nose  of  an  infected 
person  getting  into  the  mouth  or  nose  of  some  one  else  and 
causing  the  disease. 

Experiment.  —  To  discover  the  distance  germs  may  be  scattered  by  the 
"  droplet  method  of  infection." 

Materials:  Four  petri  dishes  with  sterile  agar. 

Method:  Cough  into  one  dish  of  agar  at  a  distance  of  2  feet,  into  a  second 
at  3  feet,  and  into  the  third  at  5  feet.  Hold  a  fourth  dish  2  feet  away 
but  cough  into  a  clean  handkerchief.  Cover  the  dishes  and  leave  them 
in  a  warm  dark  place  for  several  days.  Examine  them  to  see  which  has 
developed  the  greater  number  of  colonies  of  bacteria. 

Result  and  Conclusion:  What  is  the 
result  in  each  case?  What  dangers 
are  there  from  the  "  coughs  "  of  peo- 
ple having  colds  and  throat  diseases  ? 

Application:  How  can  the  spread 
of  disease  by  coughing  be  greatly 
reduced? 

Some  ways  in  which  conta- 
gious   diseases   are    spread.  - 

We    have    already    seen    that 
germs   grow   rapidly    in  moist, 

Warm  places  Where  there  is  food  Always  cough  or  sneeze  into  your 
-  ,,  TTT1  .,  .  handkerchief.  Why? 

for   them.    When    this    warm, 

moist  place  is  the  throat  or  nose,  then  evidently  the 
easiest  way  to  spread  such  diseases  is  by  coughing  or 
spitting.  The  next  time  you  are  talking  with  your  school- 
mates, stand  between  them  and  the  light  and  you  will 
notice  that  as  they  talk,  little  droplets  fly  out  of  their 
mouths  and  pass  into  the  air  in  a  constant  spray.  This 
spray  reaches  from  eighteen  inches  to  three  feet  from  the 
person  who  talks.  It  is  quite  evident  that  any  one  who 
has  germs  in  his  throat  or  mouth  could  easily  pass  these 


ig6 


HOW  DISEASES  ARE   SPREAD 


germs  out  with  these  little  droplets  to  some  one  who  stood 
within  that  three-foot  limit.  It  is  also  evident  that  any 
one  who  puts  any  article  into  his  mouth  after  it  has  been 
placed  in  the  mouth  of  one  having  a  contagious  disease 

will  probably  take  that 
disease.  One  of  the  fre- 
quent methods  of  conta- 
gion is  by  giving  your 
neighbor  a  bite  of  your 
apple  or  a  piece  of  candy 
which  has  been  in  your 
mouth. 

How  to  know  a  conta- 
gious disease.  -  -  Since 
all  who  read  this  book  go 
to  school,  we  are  most 
interested  in  diseases  that 
affect  children.  Such 
diseases  are  mumps, 
measles,  scarlet  fever, 
chicken  pox,  whooping 

A  good  way  to  spread  colds.     Explain.  COUgh,      Diphtheria,      ton- 

sillitis,   and  a  variety  of 

colds.  Practically  every  child's  disease  at  the  outset  be- 
gins with  sneezing,  running  at  the  nose,  and  a  slight  cough 
and  fever,  so  it  is  very  evident  that  if  any  one  has  any 
of  these  symptoms,  he  should  be  kept  at  home.  The 
period  from  the  time  that  the  disease  germ  begins  to  grow 
in  a  person's  body  until  the  time  that  the  symptoms 
of  the  disease  are  evident  is  called  the  incubation  period. 
During  this  period  of  time  the  disease  germs  are  growing 
in  the  body  but  not  making  themselves  known  because 


HELP  TO  FIGHT  CONTAGIOUS  DISEASES 


197 


the  poisons  which  they  give  off  have  not  been  formed  in 
large  enough  quantities  to  seriously  affect  the  person's 
system.  This  incubation  period  differs  greatly  in  different 
diseases.  With  mumps,  it  is  15  to  22  days;  in  whooping 
cough,  14  days;  in  chicken  pox,  n  to  22  days;  in  the 
case  of  measles,  8  to  15  days;  while  in  diphtheria,  it  is 
only  from  i  to  5  days.  When  one  has  been  exposed  to 
a  contagious  disease  it  is  easy  to  tell  if  he  has  taken  it; 
for  if  the  symptoms 
do  not  make  them- 
selves known  within 
the  time  of  the  incu- 
bation period,  we  may 
know  he  has  escaped. 
How  we  may  help 
to  fight  contagious 
diseases.  —  The  first 
and  biggest  thing  that 
any  person  can  do  to 
help  fight  contagious 
diseases  is  to  be  un- 
selfish. If  brother  has 
the  symptoms  of  a 
contagious  disease,  it 
is  more  trouble  to 
keep  him  at  home 
out  of  the  way  of 
other  children  than  to 
send  him  to  school. 


According  to  Health  News,  N.  Y.,  the  failure  of  a 
doctor  to  report  the  first  case  of  measles  resulted 
in  its  spread  until  there  were  270  cases. 


But  are  we  good  citizens  if  we  let  him  go?  If  he  does  go, 
he  will  surely  spread  the  disease  to  a  good  many  innocent 
boys  and  girls.  It  is  necessary  to  be  honest,  unselfish,  and 


ig8  HOW  DISEASES  ARE  SPREAD 

to  observe  health  regulations ;  if  a  contagious  disease  does 
appear  in  our  home,  we  must  see  to  it  that  the  case  is  strictly 
quarantined  from  other  members  of  the  family  and  that  all 
the  dishes,  clothes,  bed  clothes,  and  everything  else  used  by 
the  patient  are  carefully  disinfected.  Perhaps  you  already 
know  that  disinfection  by  the  use  of  some  substance  like 
chloride  of  lime,  mercury  bichloride,  lysol,  carbolic  acid, 
boiling  water,  and,  best  of  all,  sunlight,  will  kill  germs. 

How  disease  germs  may  be  killed.  —  We  have  seen 
by  means  of  experiments  that  germs  need  moisture,  warmth, 
and  food  in  order  to  grow.  Dry  air,  sunlight,  lack  of  food, 
all  are  unfavorable  to  their  growth,  but  certain  poisonous 
substances,  called  disinfectants,  kill  them  at  once.  Sub- 
stances which  simply  stop  the  growth  of  bacteria  are 
called  antiseptics.  Antiseptics  and  not  disinfectants 
should  be  used  in  cleaning  a  wound,  for  disinfectants  are 
too  harsh  for  living  tissue.  The  growth  of  bacteria  in 
foods  is  prevented  by  certain  harmless  substances,  called 
preservatives,  such  as  salt,  sugar,  vinegar,  and  spices. 

How  germs  cause  disease.  —  We  have  seen  that  there 
are  two  different  types  of  germs,  those  which  cause  disease 
and  those  which  do  not.  The  former  are  called  pathogenic, 
and  the  latter  non-pathogenic.  Some  of  the  disease  germs 
cause  trouble  by  the  formation,  as  they  grow  in  the  body, 
of  substances  which  are  poisons.  Just  as  when  we  eat  and 
work  we  give  off  wastes,  so  these  germs  give  off  wastes  which 
are  taken  into  the  blood  and  passed  around  the  body  in  the 
circulation.  These  wastes,  which  are  called  toxins,  cause 
the  symptoms  of  disease,  and  the  disease  begins  to  affect 
us  when  there  is  a  sufficient  amount  of  these  wastes  to 
make  themselves  felt.  Other  germs  destroy  tissue,  as  is 
seen  in  tuberculosis. 


ANTITOXIN    FOR    DIPHTHERIA  199 

Immunity:  natural  and  acquired.  —  Sometimes,  as  we  well 
know,  a  boy  or  girl  who  has  been  exposed  to  a  contagious 
disease  does  not  take  the  disease.  When  a  person  exposed 
to  a  catching  disease  does  not  take  it,  we  say  he  is  immune. 
Some  persons  are  more  susceptible  to  diseases  than  others. 
Just  as  in  cattle  or  other  animals,  some  resist  the  attack  of 
disease  more  than  others,  so  in  human  beings,  some  people 
easily  resist  disease  and  are  said  to  have  natural  immunity. 
It  is  a  well-known  fact  that  white  people  are  more  immune 
to  tuberculosis  than  dark  people,  while  the  black  race  is  less 
susceptible  to  malaria  than  the  white  race.  Most  important 
of  all  in  securing  immunity  is  the  condition  of  the  body  at 
the  time  we  are  exposed  to  the  disease.  If  we  are  fatigued 
from  overwork,  or  if  we  have  been  misusing  our  body  in 
any  way,  either  through  the  use  of  drugs  or  alcohol,  then 
the  blood  is  not  able  to  resist  the  toxins  of  the  bacteria  and 
we  are  less  likely  to  have  natural  mmunity  to  the  disease. 

It  is  also  possible  for  the  body  to  acquire  immunity 
against  diseases  through  the  use  of  antitoxins  and  vaccines. 
Both  antitoxins  and  vaccines  are  furnished 
free  by  the  boards  of  health  of  mosti  com- 
munities, and  as  a  study  of  the  diagram 
shows,  they  are  very  important  factors  in 
the  prevention  of  certain  diseases. 

Use  of  antitoxin  for  diphtheria.  —  Per- 


HbArtatowv. 

-used,  oiv./      usei-on./ 

loo  C»Se6 


haps  the  most  widely  known  antitoxin  is    Typhoid  antitoxin 
that  used  for  the  prevention  of  diphtheria. 


An  antitoxin  is  a  substance  which  is  pro-  from  typhoid- 
duced  by  the  living  cells  of  the  body  under  the  stimulation 
of  a  toxin  or  poison.  Each  antitoxin  will  neutralize  or 
destroy  only  the  toxin  which  caused  it  to  come  into  existence, 
and  so  in  the  preparation  of  antitoxin  for  diphtheria,  they 


2OO 


HOW  DISEASES  ARE   SPREAD 


Before  Antitorm 


. 

1884  85 8fe 87  88 89 90 91  9295  9899190001  02030405  Ot,  Oj 


Death  rote /x>nv- XiBtitheria  iiv  Tfew  eferse^  par  iO.OOO 


the  death  rate 


use   horses   into   whose   blood    is    introduced    a    certain 
amount  of  diphtheria  toxin.     This  causes  the  cells  of  the 
horse  to  manufacture  antitoxins  which  get  into  the  liquid 
part  of  the  blood  of  the 
horse.    After  two  or  three 
months  the  blood  of  the 
horse  thus  treated  has  a 
large    amount    of    anti- 
toxin in  it.     This  blood 
is  drawn  off  and  allowed 
to  clot.      The  serum  or 
liquid  part   contains  all 
of    the     antitoxin,    and 
after  preparation  with  th*e  A**140*111  has 
greatest  care  it  is  put  up 

in  small  tubes  and  is  injected  into  the  body  of  a  person 
who  either  has  diphtheria  or  who  has  been  exposed  to  the 
disease.  As  a  glance  at  the  diagram 
shows,  this  antitoxin  is  most  efficient 
in  the  early  stages  of  the  disease. 

Vaccination.  —  Another  form  of  ac- 
quired immunity  is  brought  about 
through  the  use  of  vaccines.  In  the 
case  of  vaccination  for  typhoid,  the 
dead  typhoid  germs  are  injected  into 
the  body  and  their  toxins  cause  the 
cells  of  the  body  to  form  some  substances  which  resist  the 
disease.  In  the  case  of  the  use  of  vaccine,  the  healthy  cells  in 
the  body  are  stimulated  to  produce  substances  which  cause  the 
body  to  become  immune.  In  the  case  of  the  use  of  an  anti- 
toxin, the  substances  already  prepared  are  poured  into  the 
blood  and  neutralize  the  products  formed  by  the  disease 


Deaths -p«<-100 
coases  or  Diph.tK.eria, 
Antitoxin  is  used,  oiv 
days  flnt«r-d>e.aiseo« 
•"1st  Day  No  Deaths 

2nd  Day 


4tW 
SthDa; 


Antitoxin  must  be  used  in 
the  early  stages  of  diph- 
theria to  be  of  value. 


USE   OF   THE   SCORE   CARD  201 

germs  which  are  already  there.  In  your  community  the 
board  of  health  prepares  and  gives  out  antitoxins  and 
vaccines.  These  substances  are  the  most  important  we 
have  to  fight  disease,  and  every  person  should  cooperate 
with  the  board  of  health  in  his  community  to  have  these 
substances  used.  An  outbreak  of  smallpox  occurred  a 
few  years  ago  in  Niagara  Falls,  New  York,  simply  be- 
cause a  number  of  people  refused  to  allow  themselves  or 
their  children  to  be  vaccinated  Uneducated  people 
sometimes  do  not  understand  the  reason  for  certain  hy- 
gienic actions.  Will  you  do  your  share  toward  making 
your  community  one  where  cooperation  is  the  watchword 
and  where  no  epidemics  can  occur  because  of  the  watch- 
fulness and  unselfishness  on  the  part  of  all  its  citizens  ? 

Use  of  the  score  card,  —  To  make  the  score  card  (page 
202)  useful  the  entire  class  ought  to  devote  at  least  one 
period  to  making  it  out.  It  will  first  be  necessary  for  each 
member  of  the  class  to  take  some  one  part  of  the  work  of 
finding  out  how  the  city  is  protected  against  disease  and 
then  all  of  the  information  brought  into  class  from  differ- 
ent sources  can  be  discussed,  graded  by  the  class  as  a  com- 
mittee, and  the  final  results  placed  on  the  score  cards. 


REFERENCE   BOOKS 

Broadhurst,  Home  and  Community  Hygiene.    J.  B.  Lippincott  Company. 

Chapin,  Health  First.     The  Century  Company. 

Conn,  Bacteria,  Yeasts,  and  Molds.     Ginn  and  Company. 

Gruenberg,  Elementary  Biology.     Ginn  and  Company. 

Gulick,  The  Efficient  Life.     Doubleday,  Page  and  Company. 

Harrington-Richardson,  Practical  Hygiene.     (For  teachers.)     Lee  and  Febiger. 

Hill,  The  New  Public  Health.     (For  teachers.)     The  Macmillan  Company. 

Jewett,  Town  and  City.     Ginn  and  Company. 

Lee,  Health  and  Disease.     CFor  teachers.)     Little,  Brown,  and  Company. 

Marshall,  Microbiology.     (For  teachers.)     P.  Blakiston's  Son  and  Company. 


2O2 


HOW  DISEASES  ARE  SPREAD 


SCORE  CARD.    WORK  OF  THE  BOARD  OF  HEALTH 


PER- 
FECT 
SCORE 

MY 
SCORE 

EQUIPMENT 
AND 
PERSONNEL 

Board  of  Health  active  and  free  from  politics  (5) 
Equipment  good  (5),  fair  (3),  poor  (i) 
Physicians  employed  give  entire  time  to  work  (5), 
part  time  (i) 

15 

QUARANTINE 
AND 
SERUMS 

Quarantine  laws  strictly  enforced  (5),  partly  (2) 
Contagious  diseases  reported  by  school  physicians 
(5),  not  reported  (o) 
Disinfection  required  by  law  and  law  always  en- 
forced (5),  sometimes  (i) 
Free  antitoxins  and  vaccines  (5),  not  free  but  ob- 
tainable at  all  times  (4) 

20 

HOSPITALS 
AND 
RESEARCH 

Hospitals  ample  for  community  needs  (5) 
It  has  various  types  of  hospitals  or  special  depart- 
ments 
General  (4) 
Eye,  ear,  nose,  throat  (4) 
Surgical  cases  (2) 
Maternity  (2) 
Contagious  diseases  (2) 
Tuberculosis  hospital  or  sanatoria  (4) 
Division  of  research  formed  (i) 
Bureau  of  vital  statistics  (i) 

25 

COOPERATION 
AND 
LAW 
ENFORCEMENT 

Private  institutions  cooperate  with  board  of  health. 
Cooperation   with   board    of    health  on   part  of 
school  children  (5),  parents  (5) 
Law  enforcement  on  spitting  (5) 
Laws  other  than  Interstate  Commerce  Act  on  killing 
and  sale  of  meats,  with  enforcement  of  such  laws 

(s) 

Supervision  of  food  supplies  (5) 
Law  enforcement  on   manure  heaps  and  outdoor 
privies.     Campaigns  of  health  education  started 

Cooperation   with    state   and   public  health   serv- 
ice (2) 
Cooperation  with    civic    associations    in    health  or 
clean-up  campaign  (10) 

40 

TOTAL                                                                                                          I  00 

CHAPTER  XIV 
THE  RELATION   OF  INSECTS  TO   DISEASE 

Problems.  —  i .     To  understand  the  menace  of  the  fly  to 
a  community. 

2.  To  learn  some  methods  by  which  a  community  may 
exterminate  flies. 

3.  To  understand  the  menace  of  the  mosquito  to  a  com- 
munity. 

4.  To    learn    how    malaria    is    caused,    carried,     and 
cured. 

5.  To  learn  the  relation  of  yellow  fever  to  mosquitoes. 

6.  To  learn  how  to  fight  the  mosquito. 

7.  To  understand  how  fleas,  bedbugs,  and  some  other  in- 
sects may  carry  disease. 

Experiments. —  i.   To  discover  what  food  materials  are  most  attractive 
to  flies. 

2.  To  try  the  effect  of  borax  or  kerosena  when  used  in  the  breeding 
places  of  flies. 

3.  To  see  if  oil  will  prevent  development  of  mosquitoes  in  water. 

Project    I. — TO  LOCATE   THE    "FLY    NUISANCE"    CENTERS   IN   MY 
COMMUNITY  AND  TO  ASSIST  IN  THEIR  REMOVAL. 

1.  Observe  stores,  dumps,  homes,  street  dirt,  barns,  stables,  or 
other  outhouses  for  prevalence  of  flies. 

2.  Consider  methods  of  combating  the  nuisance  in  each  case 
where  conditions  show  a  serious  menace  to  the  community. 

3.  Devise  means  of  helping  destroy  the  community  fly  menace 
by  using  chemicals,  cleaning  up,  and  by  making  and  using  fly  traps. 

4.  Work  out  in  the  laboratory  the  complete  life  history  of  the  fly 
and  report  on  the  results  to  the  class. 

203 


204       THE  RELATION  OF  INSECTS  TO  DISEASE 

Project  II.  —  To  MAKE  A  SURVEY  OF  THE  COMMUNITY  MOSQUITO 
PROBLEM. 

1.  Locate  possible  breeding  places. 

2.  Consider  methods  of  removing  favorable  breeding  places  as 
drainage,  use  of  oil,  and  "  cleaning  up." 

3.  Try  to  start  a  general  community  campaign  to  war  on  the 
mosquito. 

4.  Work  out  the  life  history  of  mosquitoes  breeding  near  home 
and  demonstrate  before  the  class. 

When  you  visit  a  town  or  a  city  for  the  first  time  and 
see  all  the  porches  screened  in,  you  say,  "  They  have 
mosquitoes  here.  I  wouldn't  want  to  live  in  this  place." 
Or,  if  in  the  summer  time  we  notice  great  swarms  of  flies 
about  stores  and  in  the  kitchens  of  the  houses  we  are  apt 
to  think:  "  This  isn't  a  very  pleasant  place  to  live  in." 
Indeed,  such  a  town  would  be  neither  a  pleasant  nor  a  safe 
place  in  which  to  live.  But  why  unsafe,  you  ask.  Why 
should  flies  or  mosquitoes  make  me  or  any  one  else  sick? 
A  moment's  thought  on  your  part,  together  with  the  addi- 
tional knowledge  that  this  chapter  will  give  you,  ought  to 
make  it  very  evident  that  mosquitoes  and  flies  are  not 
good  neighbors. 

Flies  and  foods.  —  You  have  probably  noticed  in  sum- 
mer that  a  butcher  shop  or  a  bakery  often  contains  many 
flies,  and  possibly  you  have  wondered  why  more  flies 
are  there  than  in  a  drug  store,  or  a  grocery  store,  or  a 
florist's  establishment.  The  following  experiment  will  give 
us  a  reason  why  more  flies  are  found  in  certain  places  than 
in  others. 

Experiment.  —  To  discover  what  food  materials  are  most  attractive  to  flies. 

Materials:  Six  small  butter  dishes.  The  following  food  materials :  fish 
skin,  stale  meat,  bread,  milk,  fresh  slice  of  apple,  slice  of  decaying 
banana. 


REASONS  WHY  FLIES  ARE  ATTRACTED  TO  FOODS    205 

Method:  Place  a  small  piece  of  each  food  material  on  a  butter  dish.  Place 
these  about  i  foot  apart  where  flies  have  ready  access  to  them  and 
withdraw  to  a  distance  from  which  you  can  watch  results.  Count 
the  number  of  flies  on  each  material  at  the  end  of  2,  4,  6,  8,  and  10 
minutes. 

Results  and  Conclusion:  Tabulate  the  results  and  draw  conclusions. 

Application:  What  suggestion  does  this  give  to  help  you  explain  the 
reason  for  the  number  of  flies  found  in  a  store,  in  a  shop,  or  in  your 
back  yard  ? 

The  reasons  why  flies  are  attracted  to  foods.  —  It  is 

very  evident  from  this  experiment  that  certain  foods 
are  much  more  attractive  than  other  foods  to  flies. 
It  is  also  evident  that  flies  have  a  sense  of  smell, 
or  at  least  that  they  can  distinguish  different  kinds  of 
food  in  some  way.  Unfortunately,  flies  are  attracted 
to  many  decaying  substances.  We  find  them,  there- 
fore, swarming  in  garbage  pails,  in  manure  heaps,  and 
even  in  privy  vaults  and  open  toilets.  Flies  are 
not  at  all  particular  where  they  wipe  their  feet.  A 


i.   Foot  of  fly.     2.   Growth  of  bacteria  in  agar  along  path  of  fly,  which  walked  on  it. 
3.  The  manure  pile  is  the  favorite  breeding  place  of  flies. 

study  of  the  accompanying  illustration  will  show  you 
what  happens  when  a  fly  walks  on  sterile  agar  in  a 
culture  dish.  Millions  of  germs  may  be  thus  carried 
on  the  feet  of  a  single  fly.  The  little  pads  on  the  foot  of 
a  fly  are  quite  sticky  and  as  the  fly  walks  over  a  surface, 


206       THE   RELATION  OF  INSECTS  TO  DISEASE 

germs  may  easily  be  picked  up  and  stick  to  the  pads  and 
to  the  hairs  which  cover  the  leg  and  foot.  In  a  recent 
experiment  made  at  the  Connecticut  Agricultural  Station, 
it  was  found  that  a  single  fly  might  carry  on  its  feet  from 
500  to  6,600,000  bacteria. 

Why  flies  may  carry  disease.  —  But,  you  might  say,  a 
fly  could  light  in  a  garbage  pail  or  on  decayed  food  and 
yet  might  not  carry  disease  to  me  or  anybody  else. 
True,  a  fly  might  not  carry  disease  germs  from  a  garbage 
pail  or  from  decaying  matters.  But  it  would  be  likely 
to  carry  such  germs  if  it  had  lighted  in  a  spittoon  or  if  it 
had  been  attracted  to  some  toilet  or  privy.  It  is  not 
very  pleasant  to  think  of  flies  carrying  germs  from  such 
places  to  one's  food,  but  it  is  quite  easy  in  the  sum- 
mer time  for  such  a  thing  to  be  done.  Baby's  milk,  if  ex- 
posed to  the  crawling  fly,  makes  an  excellent  place  for 
spreading  the  germs  of  typhoid  or  diarrhea,  which  multiply 
rapidly  in  milk.  Flies  also  may  carry  germs  which  cause 
tuberculosis  from  the  expectorations  left  on  the  sidewalks 
or  in  the  street  by  careless  people.  Certainly  flies  are 
a  menace  to  health,  and  it  is  our  duty  to  know  some- 
thing of  their  life  history  so  that  we  may  properly  plan 
to  destroy  them  whenever  possible. 

The  life  habits  of  flies.  —  The  common  house  fly 
seems  to  prefer  horse  manure,  human  excrement,  decaying 
kitchen  refuse  or  other  fermenting  material  in  which  to  lay 
its  eggs.  Stables  where  manure  is  not  removed  regularly 
make  an  excellent  place  for  the  breeding  of  flies.  The  fe- 
male fly  lays  from  one  to  two  hundred  eggs,  and  in  warm 
weather  these  eggs  hatch  in  from  eight  to  twelve  hours. 
They  develop  into  little  "  maggots  "  or  larvae  which  feed 
actively  for  six  to  ten  days,  depending  upon  the  tempera- 


FLIES  AND  TYPHOID   FEVER  207 

ture.  They  then  burrow  into  the  ground  under  manure 
heaps  and  are  transformed  into  brown  pupae.  After  about 
three  days  in  this  stage  they  emerge  as  adult  flies.  It  is 


The  four  stages  in  the  life  history  of  the  fly. 

evident,  therefore,  that  any  manure  which  is  left  for  from 
a  week  to  ten  days  without  turning,  or  without  being  car- 
ried from  the  stables,  becomes  a  menace  to  health.  We 
should  do  all  in  our  power  to  persuade  people  who  have 
stables  to  clean  them  out  carefully  every  day,  and  not  to 
leave  any  moist  manure  where  it  will  remain  for  over  two 
weeks  untouched,  to  put  in  oncrete  floors  under  the 
manure  heaps,  or  to  have  the  manure  treated  with  chem- 
icals to  kill  the  fly  larvae. 

Flies  and  typhoid  fever.  —  Typhoid  germs  are  found  in 
the  urine  or  excrement  of  persons  having  the  disease. 
Many  people  become  " carriers"  of  typhoid,  and  carry  the 
germs  in  their  bodies  for  months  or  even  years  after  they 
have  had  typhoid  or  even  without  ever  being  ill  with  the 
disease.  Such  people  are  a  very  serious  problem  to  the 
health  officials.  They  also  become  a  source  of  danger  be- 
cause flies  may  visit  privy  vaults  and  carry  germs  from 
these  people  to  foods,  especially  to  milk,  where  the  ty- 
phoid germs  multiply  very  rapidly.  In  New  York  it  has 
been  shown  that  typhoid  and  other  diseases  of  the  diges- 


208       THE  RELATION  OF  INSECTS  TO  DISEASE 


tive  tract  are  more  prevalent  during  the  season  when  flies 
are  abundant  than  at  any  other  time.  It  has  also  been 
shown  that  there  are  more  cases  in  New  York  close  to  the 
mouths  of  sewers  which  empty  into  the  rivers  surrounding 
Manhattan  Island.  This  is  evidently  due  to  the  fact  that 
flies  feed  upon  the  sewage  and  then  carry  the  germs  from 

this  polluted  sewage  to 
food.  A  glance  at  the  ac- 
companying chart  shows 
how  diarrhea  in  babies  is 
much  more  serious  in 
summer  time  when  flies 
are  most  abundant. 

Flies  and  disease.  - 
Flies  undoubtedly  carry 
tuberculosis  germs  also. 
They  are  known  to  feed 
upon  the  sputum  or 
"spit"  of  consump- 
tives and  they  are  often 
seen  walking  about  on 
the  edges  of  cuspidors  or 
other  receptacles  of  this 
sort.  Flies  which  feed 
upon  tuberculosis  germs 
may  keep  those  germs 

alive  in  their  bodies  for  fifteen  days.  This  shows  the  dan- 
ger of  fly  specks,  or  the  excreta  of  flies.  Flies  carry  cholera, 
leaving  the  germs  in  milk  in  the  same  way  as  they  do  in  the 
case  of  typhoid.  Bubonic  plague,  which  is  known  to  be 
carried  by  rats,  is  also  believed  to  be  carried  by  flies.  Ex- 
periments show  that  flies  may  carry  these  germs  in  their 


I/ARGC5T 
NUMBER, 
Of  DEATHS 
DURING 


Flies  are  a  serious  menace  to  children's  lives. 


HOW  TO  FIGHT  THE  FLY 


209 


bodies  for  several  days,  and  may  even  die  of  this  disease. 
Many  people  believe  that  anthrax,  smallpox,  and  other 
diseases  are  also  carried  by  flies. 

How  to  fight  the  fly.  —  From  what  we  have  just  read  it  is 
evident  that  the  proper  way  to  get  rid  of  flies  is  to  destroy 
their  breeding  places.  Any  one  may  "  swat  the  fly  "  all 
day  long  in  September  and  make  very  little  impression 
upon  the  myriads  of  flies  which  have  come  into  existence 
since  early  May.  A  few  flies  remain  alive  over  the  win- 
ter, hiding  in  cracks 
or  crannies  in  our 
houses,  and  early  in 
the  spring  they  come 
out  and  lay  their  first 
batch  of  eggs.  It  is 
evident  that  if  all 
material  containing 
the  eggs  of  flies  breed- 
ing at  this  time  could 
be  removed,  the  first 
generation  of  flies 
would  not  come  into  existence ;  but  if  this  is  not  done, 
as  soon  as  the  flies  begin  to  breed  they  multiply  with 
tremendous  rapidity. 

It  has  been  estimated  by  Professor  Hodge  that  in  three 
months,  from  May  i  to  August  i ,  a  pair  of  flies  might  pro- 
duce 5,746,670,500  flies.  This  would  be  enough  to  fill 
over  143,000  bushel  baskets.  By  the  end  of  September  he 
estimates  that  1,096,181,249,310,720,000,000,000,000  flies 
might  be  produced.  Fly  traps  and  poisons  used  in  May 
and  June  in  our  homes  will  prevent  many  flies  from  ever 
getting  an  opportunity  to  start  this  chain  of  descendants. 

H.  W.  CIV.  SCI.  COMM. 14 


What  is  the  story  told  by  this  diagram? 


210       THE  RELATION  OF  INSECTS  TO  DISEASE 

Why  not  start  early  in  your  home  ?  In  order  to  protect 
ourselves  from  disease  we  should  screen  all  out-of-door 
privies,  keep  the  garbage  cans  covered,  and  scald  them 
at  least  twice  a  week  during  the  hot  weather.  Rubbish 
heaps  should  not  be  tolerated. 

How  a  community  fights  flies.  —  After  all,  the  fly  nui- 
sance is  largely  in  the  hands  of  the  community.  If  people 
wish  a  town  to  be  free  from  flies,  they  can  have  it  so,  and  if 
they  wish  to  have  flies  as  a  nuisance,  all  they  have  to  do 
is  to  let  the  flies  breed  freely.  It  ought  to  be  the  work  of 
every  boy  and  girl  who  reads  these  paragraphs  to  arouse 
public  sentiment  in  his,  or  her,  community ;  so  that  every 
individual  who  from  selfishness  or  ignorance  allows  a  manure 
heap  to  become  a  menace  to  the  health  of  the  community  will 
realize  that  he  is  not  doing  a  fair  thing  to  the  rest  of  the 
community.  By  carrying  out  the  sanitary  laws  made  for  the 
benefit  of  the  community,  the  fly  menace  can  be  prevented. 

Experiment.  —  To  see  the  effect  of  borax  or  kerosene  when  used  in  the 
breeding  places  of  flies. 

Materials:  Borax.  Kerosene.  Table  waste  or  stale  meat.  Empty 
tin  cans. 

Method:  Make  three  portions  of  table  waste  (garbage),  or  stale  meat 
may  be  used  instead  if  preferred.  Put  one  portion  into  a  tin  can,  fill- 
ing it  half  full.  Mix  a  second  portion  with  a  tablespoonful  of  borax. 
Put  this  hits  a  second  can.  Put  the  third  portion,  thoroughly  mixed 
with  one  or  two  tablespoonfuls  of  kerosene,  into  a  third  can.  Place 
these  three  cans  where  flies  may  readily  reach  them.  Examine  them  at 
3-day  periods  for  several  weeks,  to  see  if  maggots  and  flies  develop. 

Results  and  Conclusions:  Tabulate  the  results  and  draw  conclusions. 

Some  communities,  as  Washington,  D.  C.,  have  made 
laws  which  cause  manure  to  be  placed  in  receptacles  which 
must  be  emptied  twice  a  week  in  hot  weather.  The  city 
of  New  York  requires  that  all  stables  shall  be  screened 
and  the  manure  removed  at  frequent  intervals.  All  places 


HOW  TO  START  AN  ANTI-FLY  CAMPAIGN       211 


should  have  some  efficient  laws  which  will  prevent  the 
flies  from  maturing  in  stables.  Manure  heaps  may  be 
treated  with  borax  at  least  once  a  week,  one  pound  per 
horse.  Iron  sulphate  and  lime  may  also  be  used.  This 
prevents  flies  from  breeding  in  the  manure  heaps,  but 
unless  care  is  taken  in  cleaning  the  stables,  flies  will  breed 
in  small  heaps  of  manure  that  have  been  overlooked  in 
cleaning. 

Fly  traps  and  their  use.  —  Professor  Hodge  of  the 
University  of  Florida  has  invented  a  trap  which  deserves  a 
wider  use  than  it  now  has.  This  trap  is  placed  over  a 
hole  in  the  cover  of  the  gar- 
bage pail.  If  the  cover  is  tilted 
a  little,  flies  go  into  the  garbage 
pail,  but  in  trying  to  escape 
through  the  hole  they  go  into  the 
trap.  In  this  way  many  thou- 
sands of  flies  may  be  trapped. 
One  of  the  best  ways  to  help  keep 
down  the  fly  is  to  have  fly  traps 
placed  in  the  stable.  In  the 
house,  while  fly  traps  and  fly  paper 
may  be  used,  the  best  method 
is  the  simpler  one  of  poisoning 
flies  by  adding  a  one  to  two  per  cent  formaldehyde 
solution  to  milk  sweetened  with  a  little  sugar.  If  all  other 
liquids  are  covered  up,  flies  will  go  to  the  poison  in  great 
numbers.  Where  flies  are  found  all  food  which  attracts 
them  at  home  and  in  stores  should  be  screened. 

How  to  start  an  anti-fly  campaign.  —  One  of  the  best 
ways  for  boys  and  girls  to  interest  themselves  in  civic 
betterment  is  to  start  an  anti-fly  campaign.  For  this 


Qccrbatf 
Cctrv 


One  of  the  best  ways  to  trap  flies. 


212       THE  RELATION  OF  INSECTS  TO  DISEASE 

purpose  your  school  class  in  general  science  or  biology  can 
be  used.  Advertising  material  can  be  secured;  the  news- 
papers will  help  you ;  even  the  churches  will  probably  be 
willing  to  aid  in  such  a  good  work.  The  American  Civic 
Association,  with  offices  in  Washington,  D.  C.,  will  assist 
you  in  starting  the  campaign.  If  public  sentiment  can  be 
aroused  by  means  of  meetings,  your  city  will  wake  up, 
make  effective  laws,  and  see  that  they  are  enforced. 

The  life  history  of  mosquitoes.  —  We  all  know  that 
mosquitoes  are  found  in  some  localities  and  not  in  others. 
The  mosquito  nuisance  is  very  largely  related  to  the  presence 
of  water,  and  we  know  that  wherever  marshes  are  found 
there  we  find  mosquitoes  in  abundance.  If  we  examine 
them  carefully,  we  are  able  to  distinguish  several  kinds. 
As  a  matter  of  fact,  there  are  over  340  different  species  of 
mosquitoes.  Of  those,  the  ones  that  we  are  most  likely  to 
meet  are  the  culex,  and  the  anopheles. 

So  far  as  we  know,  mosquitoes  all  lay  their  eggs  in 
quiet  water,  stagnant  pools,  slow-running  brooks,  rain 
barrels  and  cisterns,  stopped-up  gutters,  even  tin  cans  or 
broken  crockery  found  in  rubbish  heaps.  These  places 
may  breed  enough  mosquitoes  to  make  life  miserable  for 
people  in  the  immediate  neighborhood.  The  common 
culex  lays  from  one  to  two  hundred  eggs  in  small  rafts. 
The  anopheles  or  malarial  mosquito  lays  its  eggs  in 
scattered  groups.  The  eggs  of  both  mosquitoes  usually 
hatch  in  from  36  to  48  hours,  forming  little  segmented 
or  jointed  larvae,  which  we  call  "  wigglers."  They  pro- 
pel themselves  through  the  water  with  a  curious,  jerky 
motion,  coming  to  the  surface  to  breathe.  They  take 
in  air  through  a  tube  located  near  the  hind  end  of  the 
body. 


HOW  MOSQUITOES  ARE  HARMFUL  213 

After  a  week  or  ten  days  the  front  end  of  the  body  be- 
comes larger  and  they  are  called  pupae.  They  now  breathe 
through  two  tubes  near  the  back  of  the  very  much 
enlarged  head.  During  this  stage  they  are  much  quieter 
and  do  not  eat.  After  a  week  or  more  the  pupa's  skin 
splits  down  the  back  and  the  adult  mosquito  emerges. 
This  life  history  may  take  but  little  more  than  two 
weeks,  and  the  adult  mosquito  may  then  begin  laying 
eggs  again.  Professor  Hodge  has  estimated  that  the 
descendants  from  a  single  mosquito  might  amount  to 
2,000,000,000,000,000,000,000,000,000,000,000,000,000  in- 
dividuals in  the  course  of  a  short  summer  season.  Of 
course,  many  of  these  mosquitoes  die  from  lack  of  food  or 
for  other  reasons,  but  this  shows  how  rapidly  mosquitoes 
breed. 

How  mosquitoes  are  harmful.  —  They  prevent  our  en- 
joyment at  the  close  of  summer  days  when  we  would  like 
to  be  out  in  the  garden.  They  are  a  pest  along  the  shores 
of  our  lakes,  rivers,  and  ocean  beaches.  The  salt-marsh 
mosquito  is  one  of  the  greatest  pests  of  the  eastern  and 
western  coasts.  Other  kinds  of  mosquitoes,  notably  the 
anopheles,  which  carries  malaria,  and  stegomyia,  which  car- 
ries yellow  fever,  are  very  harmful.  In  our  Civic  Science 
in  the  Home,  we  read  how  the  experiments  of  Dr.  Ross 
of  the  English  Army,  based  upon  his  belief  in  the  theory  of 
Sir  Patrick  Manson,  resulted  in  the  discovery  of  the  mala- 
rial parasite  in  the  body  of  the  anopheles  mosquito.  We 
also  read  how  Dr.  Warren  and  Dr.  Manson,  son  of 
Sir  Patrick  Manson,  verified  Ross's  discovery  by  proving 
that  mosquitoes  which  had  bitten  malarial  people  could 
carry  malaria  to  others.  We  shall  now  learn  a  little  more 
about  the  disease. 


214       THE  RELATION  OF  INSECTS  TO  DISEASE 

Malaria.  —  For  a  good  many  centuries  the  development 
of  certain  areas  in  the  world  had  been  retarded  by  malaria. 
Italy  suffered  greatly,  until  she  discovered  that  the  exter- 
mination of  mosquitoes  meant  the  elimination  of  malaria. 
Many  tropical  countries  are  backward  in  their  growth  and 
in  their  production  simply  because  laborers  are  not  able  to 


Notice  how  malaria  decreased  in  a  town  in  Arkansas  after  mosquito  control  work 
such  as  draining  swamps  and  screening  houses  was  begun. 

work  on  account  of  malarial  fever.  In  some  parts  of  the 
South  there  are  regions  where  malaria  is  so  prevalent  that 
from  twenty  to  thirty  per  cent  of  the  people  living  there 
have  the  disease.  Although  the  death  rate  from  malaria 
in  this  country  is  low  (only  3  per  100,000),  yet  the  number 
of  persons  who  are  kept  from  doing  a  full  week's  work  is 
very  great.  It  is  estimated  that  the  cost  in  dollars  to  the 
people  of  this  country  is  $100,000,000  a  year  from  malaria. 
It  is  time,  then,  that  we  took  every  means  to  stamp  out 
this  disease. 


WHAT  CAUSES  MALARIA? 


215 


What  causes  malaria  ?  —  The  malarial  mosquito,  anoph- 
eles, does  not  cause  malaria.  It  transfers  the  disease. 
The  cause  is  a  tiny  one-celled  animal  parasite.  In  order  to 
live,  this  little  animal  (plasmodium  malariae)  must  pass 
part  of  its  life  in  the  body  of  the  mosquito  and  part  in  the 
blood  of  a  human  being.  When  the  anopheles  mosquito 
sucks  the  blood  from  a  person  having  malaria,  the  parasite 
passes  with  the  blood  into  the  stomach  of  the  mosquito. 


Life  history  of  the  malarial  parasite. 

It  passes  part  of  its  life  in  the  walls  of  the  mosquito's  stom- 
ach. It  multiplies  very  rapidly  and  gets  into  the  body 
fluids  of  the  mosquito  and  from  there  into  its  salivary 
glands.  The  mosquito's  mouth  waters  when  it  starts 
to  suck  the  blood  from  a  person,  and  some  of  these  little 
parasites  are  transferred  into  the  blood.  Here  they  enter 
the  red  corpuscles,  and  multiply  rapidly.  Eventually  they 
fill  the  corpuscles  full  of  little  spores  which  break  the  cor- 
puscle down,  get  into  the  blood,  and  then  each  spore 
enters  another  corpuscle.  Thus  are  formed  millions  upon 
millions  of  these  little  parasites,  each  in  a  different  corpuscle. 
When  the  corpuscle  is  broken  down,  a  small  amount 


216       THE  RELATION  OF  INSECTS  TO  DISEASE 

of  toxin  or  poison  is  released  into  the  blood.  The 
chill  and  fever  of  malaria  is  due  to  the  breaking  down 
of  these  blood  corpuscles  and  the  subsequent  release 
of  the  poison. 

How  malaria  is  cured.  —  Of  course,  any  one  having 
malaria  may  move  away  from  the  place  where  it  was 
received,  but  since  the  spores  remain  in  the  blood,  attacks 
of  malaria  may  recur  from  time  to  time.  The  only  known, 
cure  is  quinine.  But  as  this  has  an  effect  upon  a  per- 
son's health,  it  should  only  be  given  under  the  advice  of 
a  physician. 

Yellow  fever  and  its  relation  to  mosquitoes.  —  In  former 
times  yellow  fever  was  one  of  the  most  terrible  epidemic 
diseases  of  this  country,  especially  in  the  South  and  along 
the  coast.  In  1878,  12,000  deaths  and  125,000  cases  oc- 
curred in  three  southern  states  alone.  In  1897  another 
great  outbreak  of  yellow  fever  occurred  in  New  Orleans. 
In  1906  still  another  outbreak  occurred  in  New  Orleans, 
but  it  was  quickly  stopped  by  the  discoveries  of  the  army 
commission  headed  by  Dr.  Walter  Reed.  These  discov- 
eries make  one  of  the  most  thrilling  stories  of  heroism 
connected  with  our  army.  For  a  great  many  years  Ha- 
vana, Cuba,  had  been  a  hotbed  of  yellow  fever.  In  the 
summer  of  1900  a  commission  of  four  United  States  army 
surgeons  worked  there.  Up  to  this  time  there  had  been 
two  theories  as  to  the  transference  of  yellow  fever.  The 
prevailing  one  was  that  it  was  given  by  contact  with 
matter  given  off  from  the  patient.  The  other  theory  was 
that  it  was  transferred  by  mosquitoes.  Dr.  Carroll,  one 
of  this  group,  was  the  first  man  to  allow  himself  to  be 
bitten  by  a  mosquito  carrying  the  yellow  fever  germ. 
Dr.  Carroll  had  a  severe  attack  but  recovered,  while  Dr. 


YELLOW  FEVER  AND   MOSQUITOES 


217 


ffOOM 


MOMOCCW/WW 
MOTfffffffAN,  tMO 


J.J.MOflAN 

two  roo/c 


Jesse  Lezear,  who  also  allowed  himself  to  be  bitten  by  an 
infected  mosquito,  gave  up  his  life  as  a  result  to  prove  the 
theory.  A  little  later  another  experimental  laboratory  was 
established,  and  two  young  soldiers,  John  R.  Kissinger  and 
John  J.  Moran,  volunteered  their  services  in  the  cause  of 
humanity.  These  men  lived  for  twenty  days  and  nights 
in  a  small,  poorlv  ven- 
tilated  room  with  a 
temperature  over 
ninety  degrees,  in 
close  contact  with 
articles  of  clothing 
and  other  materials 
taken  directly  from 
persons  who  had  died 
of  yellow  fever.  The 
soldiers  were,  how- 
ever, all  of  this  time 
screened  so  that  no 
mosquitoes  could 
come  near  them.  At  the  end  of  twenty  days  they  were 
perfectly  well.  Moran  then  allowed  himself  to  be  bitten  by 
a  stegomyia  mosquito  which  was  known  to  have  bitten  a 
yellow  fever  patient.  He  came  down  with  the  disease, 
but  fortunately  recovered.  .These  results  showed  un- 
doubtedly that  yellow  fever  is  carried  by  the  stegomyia 
mosquito. 

This  discovery  made  possible  our  work  on  the  Panama 
Canal.  It  is  reported  that  when  the  French  government 
was  working  on  the  canal,  eighteen  young  French  engineers 
came  over  in  one  vessel  and  within  a  month  all  but 
one  died  of  yellow  fever,  while  of  thirty-six  nurses 


Camp  Lezear,  where  first  experiments  to  determine 
if  the  mosquito  carried  yellow  fever  were  per- 
formed. 


218       THE  RELATION  OF  INSECTS  TO  DISEASE 

brought  over,  twenty-four  died  of  the  fever  in  a  short 
time.  As  soon  as  the  United  States  Government  applied 
the  knowledge  gained  in  Havana,  the  Canal  Zone  rapidly 
became  safe  to  live  in.  The  last  case  of  yellow  fever 
occurred  in  this  district  in  May,  1906.  This  is  a 


A  building  in  the  Canal  Zone  protected  by  screens. 

splendid   tribute   to   the   effective    work    of    the    United 
States  army  surgeons. 

Experiment.  —  To  see  if  oil    will  prevent  development  of  mosquitoes  in 
water. 

Materials:  Two  pails  or  large  tin  cans.     Kerosene. 

Method:  Fill  two  pails  with  water.  Place  these  out  of  doors  close  to 
bushes  or  shrubs  where  mosquitoes  are  found.  Pour  a  tablespoonful 
of  kerosene  upon  the  water  in  one  pail.  Let  them  remain  for  several 
weeks,  examining  every  3  days  for  the  presence  of  wigglers. 

Results  and  Conclusion:  What  are  the  results  ?  What  is  the  value  of  the 
oil  in  helping  to  reduce  the  mosquito  evil? 

How  to  exterminate  mosquitoes.  —  From  what  we  have 
already  learned  about  mosquitoes  it  is  evident  that  in  order 
to  destroy  them  we  must  first  destroy  their  breeding  places. 
Swamps  and  pools,  slow-running  streams,  ditches,  cesspools, 
rain  barrels  and  catch  basins,  even  hollow  trees  or  broken 
receptacles  may  be  breeding  places.  Mosquitoes  are  likely 


PROTECTION  IN  HOME  AGAINST  MOSQUITOES      219 

to  breed  in  any  place  that  will  hold  water  lor  two  weeks  in 
warm  weather.  Our  first  effort  should  be,  therefore,  to 
clean  up  all  dumps  where  broken  cans  or  crockery  exist, 
screen  all  rain  barrels,  cisterns,  and  privy  vaults,  ditch 
swamps,  and  where  the  latter  is  not  possible,  place  crude 
oil  upon  them.  It  can  easily  be  proved  that  the 


A  health  officer  inspecting  swamp  water 
for  mosquito  larvae. 


A  member  of  sanitary  squad  applying 
crude  oil  to  swamp. 


larvae  and  pupae  of  mosquitoes  are  quickly  killed  if  a  film 
of  oil  is  placed  over  the  surface  of  the  water  where  they 
breed.  Such  a  film  not  only  prevents  the  female  from  lay- 
ing her  eggs  in  the  water,  but  clogs  up  the  breathing;  holes 
of  the  larvae  and  pupae  in  the  water  and  kills  them. 

Small  fish  may  be  introduced  into  the  ponds  and  streams. 
The  best  fish  for  the  purpose  of  ridding  a  pond  of  mosqui- 
toes are  top  minnows,  goldfish,  sticklebacks,  and  killifish. 
Night-flying  birds,  especially  night  hawks  and  swallows, 
feed  on  mosquitoes.  Toads,  frogs,' bats,  and  dragon  flies 
also  are  active  enemies,  and  should  be  protected  wherever 
mosquitoes  abound. 

Protection  in  the  home  against  mosquitoes.  —  The  most 
effective  protection,  of  course,  is  to  have  no  breeding 


220       THE  RELATION  OF  INSECTS  TO  DISEASE 

places  near  one's  home,  for  most  mosquitoes  fly  only  a 
short  distance  from  where  they  breed.  Screens  on  all 
windows  become  a  necessity  if  we  are  to  sleep  in  peace. 
In  the  tropics  a  bed  net  is  used,  which  effectively  keeps  out 
mosquitoes  that  get  into  the  rooms.  The  use  of  pyre- 
thrum  powder  or  sulphur  for  fumigation  is  also  helpful. 
Pyrethrum  powder  burned  in  the  room  usually  stupefies  the 
mosquitoes  so  that  they  can  be  killed.  Those  of  us  who 
go  fishing  in  mosquito  season  know  that  the  most  effective 
"  dope "  is  made  of  oil  of  citronella.  A  very  useful 
preparation  is  composed  of  i  ounce  oil  citronella,  i  ounce 
spirits  of  camphor,  and  ^  ounce  oil  of  cedar  mixed  with 
4  ounces  of  vaseline. 

How  the  community  may  fight  the  mosquito  nuisance.  - 
The  strongest  factor  in  fighting  mosquitoes  or  flies  in  a  com- 
munity is  public  opinion.  Since  educated  people  make 
public  opinion,  and  since  children  of  school  age  are  being 
educated  along  these  lines,  it  goes  without  saying  that 
they  can  do  much  towards  improving  conditions.  The 
school  children  of  San  Antonio,  Texas,  took  up  the  task  of 
exterminating  the  breeding  places  of  mosquitoes  and  elim- 
inated malaria  within  two  years  after  they  started  to 
work.  This  is  only  one  example  of  what  has  been  done  in 
many  other  places  throughout  the  United  States.  The 
best  way  to  start  work  is  for  the  general  science  class  or 
the  biology  class  to  make  a  survey  of  the  community  and 
find  out  where  the  breeding  places  are,  then  go  to  the 
board  of  health  or  the  school  board  and  get  its  assistance. 
Oil  all  the  places  that  cannot  be  taken  care  of  otherwise, 
have  the  children  clean  up  yards  or  vacant  lots  where 
breeding  places  exist,  and  then  show  the  public,  by  means 
of  articles  in  the  newspapers,  and,  if  possible,  through 


RELATION  OF  FLEAS  TO  THE  BUBONIC  PLAGUE     221 


public  meetings,  what  other  work  there  is  to  be  done.  Re- 
port the  facts  of  your  survey  to  the  county  and  state 
health  offices.  See  what  they  will  do  to  help.  By  means 
of  such  work  the  mosquito  menace  can  be  reduced  if  not 
eliminated. 

The  relation  of  fleas  to  the  bubonic  plague.  —  Plague, 
the  Black  Death  of  the  ancients,  was  estimated  in  the  four- 
teenth century  to  have  killed  25,000,000  persons  in  Europe 
alone.  It  is  now  prevalent  in  Asia,  and,  as  we  know  from 
the  recent  experience  of  San  Francisco,  its  introduction 


RATS?, 

GET  A 

SANITAR 

BACE  CAD 
ROUT 

THE  RAT 


Do  rats  find  anything  to  attract  them  to  your  back  yard? 

into  this  country  is  always  possible.  Rats  and  ground 
squirrels  become  infected  with  the  disease,  and  thus  fleas, 
which  live  upon  them.  When  a  rat  dies  of  plague,  fleas 
leave  this  rat  and  go  to  another,  or,  possibly,  to  a  human 
being ;  then  if  they  bite  a  human  being  he  would  be  inocu- 
lated with  the  plague.  In  San  Francisco  fully  1,000,000 
rats  were  killed,  thus  partially  removing  one  means  of  in- 
fection. To  exterminate  rats  completely  is  almost  impos- 
sible. General  clean-up  measures  are  necessary,  and  by 
the  use  of  pyrethrum  powder,  benzine,  or  naphthalene  flakes 
one  may  rid  a  house  of  fleas. 


222        THE  RELATION  OF  INSECTS  TO  DISEASE 

The  relation  of  lice  to  trench  fever.  —  During  the  World 
War  many  problems  of  disease  transmission  were  solved 
and  conquered,  thanks  to  the  splendid  work  of  the  sanitary 
and  medical  officers  of  the  allied  armies.  One  serious 
menace  to  the  soldiers  was  trench  fever.  This  fever  was 


A  clean-up  campaign  will  do  much  to  rid  a  city  of  rats,  mice,  and  fleas. 

proven,  by  experiments  performed  on  66  volunteers  from 
various  units  in  the  ambulance  and  hospital  service,  to  be 
transferred  by  the  body  louse  or  "  cootie  "  as  the  soldiers 
called  it.  Germs  which  caused  the  disease  were  present 
in  the  blood  and  were  transferred  by  the  mouth  parts  of 
the  "  cootie."  After  this  discovery,  disinfecting  plants 
were  established  for  men  coming  in  from  the  trenches, 
their  clothes  were  carefully  disinfected  as  well,  and  the 
danger  was  greatly  reduced. 

Other    diseases    carried    by   insects.  —  Many   tropical 
diseases  are  known  to  be  carried  bv  insects.     The  most 


OTHER  DISEASES   CARRIED   BY  INSECTS         223 

dreaded  of  these  is  "  sleeping  sickness."  This  is  caused 
by  a  tiny  one-cell  animal  called  a  trypanosome  which  is 
carried  by  the  tsetse  fly.  This  fly  we  find  not  more 
than  150  feet  from  the  banks  of  streams  or  lakes,  so  that 
it  is  quite  possible  that  the  disease  may  be  successfully 
fought  by  keeping  away  from  bodies  of  water  where  these 
flies  live.  Elephantiasis  is  caused  by  a  wormlike  parasite 
called  filiara  and  is  carried  by  mosquitoes  and  insects. 
Dengue  or  "  break-bone  fever,"  as  it  is  called,  is  a  rare 
but  an  intensely  painful  disease  caused  by  a  one-celled 
animal,  and  carried  by  the  culex  mosquito.  Other  diseases 
carried  by  insects  are  "  malta  fever,"  "  kala-azar  "  and 
probably  leprosy. 

REFERENCE   BOOKS 

Barber,  First  Course  in  General  Science.     Henry  Holt  and  Company. 

Directions  for  Making  a  Home.nade  Flytrap.     International  Harvester  Company, 

Chicago. 

Doane,  Insects  and  Disease.     Henry  Holt  and  Company. 
Gruenberg,  Elementary  Biology.     Ginn  and  Company. 
Hodge,  Civic  Biology.     Ginn  and  Company. 
Howard,  The  House  Fly.     F.  A.  Stokes  Company. 
Hunter,  A  Civic  Biology.     American  Book  Company. 
Hunter,  Laboratory  Problems  in  Civic  Biology.     American  Book  Company. 
Jackson,  et  al.,  The  Housefly  at  the  Bar.     Merchants'  Ass'n  of  New  York. 
Jewett,  Town  and  City.     Henry  Holt  and  Company. 
Kellogg,  American  Insects.     (Chapter  on  Insects  and  Disease.)     Henry  Holt  and 

Company. 

Peabody  and  Hunt,  Elementary  Biology.     The  Macmillan  Company. 
Reprint,  436,  Control  of  Communicable  Diseases.     Public  Health  Service. 
Ritchie,  Primer  of  Sanitation.     World  Book  Company.  . 

Ross,  The  Reduction  of  Domestic  Flies.     J.  B.  Lippincott  Company. 
Smith  and  Jewett,  Introduction  to  the  Study  of  Science.     The  Macmillan  Company. 
Trafton,  Science  of  Home  and  Community.     The  Macmillan  Company. 
Winslow,  Healthy  Living.     C.  E.  Merrill  Company. 
Wood,  Sanitation  Practically  Applied.     (For  teachers.)     John  Wiley  and  Sons. 


CHAPTER   XV 
DISPOSAL   OF  WASTES 

Problems.  —  i.  To  learn  about  different  methods  of  sew- 
age disposal  in  a  community. 

2.  To  understand  the  construction  and  operation  of  a 
septic  tank. 

3.  To  see  how  streets  are  cleaned  and  how  to  help  keep 
them  clean. 

4.  To  know  how  other  wastes  are  best  disposed  of> 

Experiment. —  i.  To  compare  the  wet  and  the  dry  methods  of  street 
cleaning. 

Project  I.  —  To  MAKE  A  STUDY  or  THE  DISPOSAL  OF  WASTE  IN  MY 

OWN  COMMUNITY. 

1.  What  regulations  apply  to  the  disposal  of  waste? 

2.  To  what  extent  are  the  regulations  observed? 

3.  Is  the  system  effective?     Does  it  pay  for  itself? 

4.  Is  any  part  of  the  system  self-supporting? 

5.  How  are  the  streets  cleaned?     How  often? 

6.  Are  there  better  methods  in  use  in  any  communities  that  you 
know  of  or  have  read  of? 

Most  boys  and  girls  who  read  this  paragraph  have  seen 
men  at  work  digging  a  sewer.  You  have  noticed  how  the 
long,  deep  excavation  is  always  graded  so  that  as  the  big 
pipe  is  constructed  at  the  bottom  it  always  has  a  gentle 
grade  toward  the  outlet  in  some  distant  part  of  the  town. 
Perhaps  if  you  followed  it  to  its  end  you  would  find  that  it 
emptied  into  a  river  or  some  large  body  of  water.  In  such  a 

224 


SEWAGE  DISPOSAL  INTO  RIVERS 


225 


sewer  you  may  find  openings  from  the  street  into  which  the 
rainfall  may  pass,  with  large  catch-basins  to  hold  the  solid 
matter.  You  may  also  notice  that  each  house  along 
the  line  of  this  sewer  is 
connected  with  it  by  a 
smaller  pipe. 

Purpose  of  sewer  sys- 
tem. -  -  Sewers  date 
back  to  Roman  times. 
The  great  Cloaca  Max- 
ima emptied  into  the 
Tiber  just  beyond  the 
Forum  of  ancient  Rome. 
Its  purpose  was  then,  as 
is  the  purpose  now  of  cer- 
tain sewers,  to  carry  off 
the  overflow  or  rainfall 
and  street  wastes. 
Since  some  of  these  wastes  are  solid,  the  sewer  system 
must  have  a  grade  sufficient  to  carry  along  solid  matter 
with  the  liquid  that  passes  off.  If  a  city  has  a  means  of 
carrying  this  sewage  into  a  body  of  water,  then  a  single  set 
of  pipes  having  connections  with  houses  and  with  the  street 
pipes  by  means  of  catch  basins  is  sufficient.  Thus  a  sewer 
serves  to  carry  off  rainfall  as  well  as  to  dispose  of  its  house- 
hold waste.  But  if  a  community  has  to  dispose  of  its 
sewage  in  some  other  way,  then  a  separate  system  of  pipes 
is  usually  laid  for  household  waste  so  that  the  sewage  will 
not  be  too  dilute  when  it  is  treated  at  the  disposal  plant. 

Sewage  disposal  into  rivers.  —  Sewage  consists  of  about 
one  part  of  organic  matter  to^one  thousand  parts  of  water. 
In  rapidly  flowing  rivers  a  small  amount  of  sewage  may  be 

H.  W.  CIV.  SCI.  COMVt.  —  15 


Men  at  work  building  a  large  sewer. 


226 


DISPOSAL  OF  WASTES 


carried  off  without  harm,  since  the  bacteria  of  decay  ad- 
hering to  the  stones  in  the  rivers  act  on  the  solid  wastes 
and  soon  break  them  down  into  harmless  liquid  substances. 
But  in  a  large  city,  sewage  disposal  is  a  big  problem,  both 
because  of  the  volume  of  sewage,  its  odor,  and  the  possi- 
bility of  the  spread  of  disease  from  it.  The  city  of  New  York 
empties  daily  450,000,000  gallons  of  sewage  into  the  rivers 
surrounding  it;  thus  Manhattan  Island  is  bathed  in  dilute 


Chicago  drainage  canal. 

sewage.  Chicago,  a  few  years  ago,  discharged  its  sewage 
into  Lake  Michigan.  At  that  time  a  large  number  of  ty- 
phoid cases  existed  in  the  city,  and  it  was  discovered  that 
some  of  the  sewage  found  its  way  to  the  intake  of  the  city 
water  supply  in  the  lake  about  two  miles  from  the  shore. 
Chicago  then  spent  $40,000,000  to  build  a  drainage  canal 
which  connected  the  Chicago  River  with  the  Des  Plaines 
River.  Through  this  canal  the  water  of  Lake  Michigan 
flowed  into  the  Mississippi,  carrying  the  sewage  of  Chicago 


SEPTIC  TANKS   FACTORS   IN  SEWAGE  DISPOSAL      227 

with  it.  The  city  of  St.  Louis  brought  suit  against  the  city 
of  Chicago,  attempting  to  prevent  tne  use  of  this  drainage 
canal,  but  the  verdict  given  was  "no  cause  for  action" 
because  it  was  found  that  Mississippi  water  about  St.  Louis 
contained  no  more  germs  than  it  did  before  the  canal  was 
built.  This  shows  that  sewage,  after  flowing  long  distances, 
becomes  very  largely  purified.  Harmful  germs  are 
gradually  killed  off  by  the  action  of  sunlight  and  oxygen 
and  from  lack  of  food. 

Septic  tanks  as  factors  in  sewage  disposal.  —  Where 
sewage  cannot  be  run  into  a  body  of  water  the  problem  is 
not  so  easy.  One  method  is  to  pass  the  sewage  to  a  disposal 
plant.  We  have  already  seen  that  in  rural  communities 
where  no  sewage  system  exists,  the  septic  tank  is  the 
best  method  for  proper  sewage  disposal.  In  this  tank  the 
solid  wastes  are  acted  upon  by  certain  bacteria  which  thrive 
without  air  (the  anaerobic  bacteria) .  These  cause  the  com- 
plex waste  substances  to  break  down  into  simpler  ones. 
Since  a  septic  tank  soon  becomes  coated  with  grease 
from  the  household  waste,  it  becomes  practically  air  tight 
and  then  forms  an  excellent  place  for  these  bacteria  to 
work. 

In  somewhat  the  same  way  septic  tanks  on  a  larger  scale 
are  ussd  in  the  city  disposal  plants.  These  plants  are 
used  to  decompose  the  sewage.  Then  the  sewage  is  passed 
through  screens  to  remove  solid  matter  and  the  clean 
sewage  is  passed  on  to  contact  filter  beds  of  broken  stone, 
where  certain  other  kinds  of  bacteria  which  live  in  the  air 
complete  the  process  of  breaking  down  or  oxidizing  the 
organic  matter  which  was  begun  in  the  septic  tank.  The 
fluid  which  is  drawn  off  is  absolutely  harmless  and  nearly 
odorless.  Such  filter  beds,  however,  can  only  be  used  a 


228 


DISPOSAL   OF  WASTES 


part  of  each  day,  so  that  a  large  city  requires  a  considerable 
amount  of  space  devoted  to  this  purpose.  Some  small 
communities  use  sand  filter  beds  for  the  disposal  of  sewage 
as  it  passes  through  the  septic  tanks.  The  sand  filter  is 


3eptic  Tank: 


Sec  3voL> 


Septic  tank  and  sand  filters  used  to  purify  sewage. 

much  more  efficient  than  the  contact  bed,  although  it  filters 
much  less  sewage  in  the  same  time. 

Sewage  farms.  —  In  some  small  cities  in  this  country, 
and  in  larger  ones  in  Europe,  sewage  is  taken  without 
treatment  and  allowed  to  pass  by  a  system  of  irrigation 
ditches  into  areas  of  sandy  soil.  The  soil  thus  fertilized 
is  made  use  of  for  farm  purposes  by  the  city.  While  this 
method  is  useful  for  a  time,  it  does  not  seem  practical  for 
long  periods  of  time,  as  the  land  becomes  water  soaked  and 
unfit  for  cultivation. 


HOW  THE  STREETS  ARE  KEPT  CLEAN 


229 


The  city  care  of  sewage.  —  In  most  large  communities 
we  have  a  department  of  sewers.  The  cost  of  the  sewers 
and  their  maintenance  is  put  in  as  part  of  the  city  budget 
Property  owners  usually  pay  directly  for  sewers  which  pass 
by  their  land  and  which  they  use.  The  cost  of  the  larger 
trunk  sewers  and  the  sewage  disposal  plants  is  assessed  upon 
the  city  as  a  whole,  since  the  entire  city  gets  the  benefit. 

How  the  streets  are  kept  clean.  —  Most  of  us  are  familiar 
with  the  "  White  Wings  "  seen  in  many  of  our  city  streets. 
These  street  cleaners,  espe- 
cially in  large  cities,  like  New 
York  and  Chicago,  form 
quite  an  army,  over  three 
thousand  men  being  em- 
ployed by  the  city  of  New 
York  for  the  work.  Their 
work  is  to  clean  the  streets 
with  hand  brooms,  brushes 
and  machines ;  to  flood  the 
streets,  usually  at  night,  and 
to  assist  in  the  collection  of 

the  sweepings  from  the  streets.  Most  large  communities 
own  street-sweeping  machines  which  are  far  more  efficient 
and  do  more  work  than  a  number  of  men.  The  sweepings 
are  collected  in  carts  and  then  disposed  of.  It  has  been 
found  that  very  many  street  cleaners  are  subject  to  tuber- 
culosis. This  indicates  the  need  of  the  enforcement  of 
a  law  against  spitting  in  the  streets.  We  know  that  such 
laws  when  made  are  rarely  observed. 

Experiment.  —  To  compare  the  wet  and  the  dry  methods  of  street-cleaning. 
Materials:   Petri  dishes.     Sterile  agar. 
Method:    If  possible,  select  two  localities  where  streets   are  cleaned  dif- 


"  White  wings. " 


230 


DISPOSAL  OF  WASTES 


ferently :  one  by  dry  sweeping  and  the  other  by  wet  cleaning.  Ex- 
pose a  petri  dish  to  the  air  in  each  locality  for  five  minutes.  Put  the 
dishes  away  in  a  dark  warm  place  for  three  or  four  days.  Instead  of 
the  two  places  cleaned  as  above,  the  experiment  may  be  carried  out  by 


Vacuum  cleaning  in  the  street. 

exposing  one  dish  in  the  street  after  a  rain  and  the  other  dish  in  dry 

weather  while  the  street  is  being  swept. 
Result  and  Conclusion:   Compare  the  number  of  bacteria  colonies  which 

develop  in  the  two  dishes.     Explain. 
Application:  Which  method  of  street  cleaning  would  you  ^advise  for  your 

neighborhood  ? 

Disposal  of  ashes  and  garbage.  —  The  garbage  may  be 
defined  as  scraps  from  the  kitchen,  waste  animal  matter, 
or  vegetables  unfit  for  use.  Rubbish  includes  tin  cans, 
broken  glass  and  crockery,  waste  paper  and  rags,  while  ashes 
are  the  remains  from  fuel.  Since  these  substances  are  so 
different,  most  communities  require  that  they  shall  be  put 


GARBAGE  REMOVAL 


231 


out  and  collected  separately.  Ashes  should  be  kept 
covered,  so  that  our  streets  may  not  be  filled  with  dirt 
during  a  high  wind.  Papers  and  tin  cans  should  be 
placed  in  separate  receptacles.  Dr.  Rosenau  of  Har- 
vard has  estimated  that  the  waste  in  New  York  amounts 
to  one  ton  a  person  a  year.  This  means  over  five  mil- 
lion tons  of  waste  has  been  collected  annually  in 
this  city  alone.  The  ashes  may  be  used  in  filling  in 
marshes  or  tidal  fiats,  and  much  valuable  land  is 
thus  formed.  A 
large  part  of  Boston 
lies  on  land  thus  re- 
claimed, while  the 
park  along  the  lake 
front  of  Chicago  is 
largely  built  on  city 
ashes. 

Collection  of  rub- 
bish. -  -  In  many 
communities  a  good 

price  is  paid  for  the  privilege  of  collecting  rubbish.  Papers 
and  rags  are  used  for  papermaking;  the  iron,  tin,  and 
solder  from  old  cans  may  be  used  over  again,  and  organic 
matter  can  be  used  for  fertilizers.  In  some  small  towns 
certain  men  are  licensed  to  collect  garbage,  rubbish,  and 
ashes,  but  an  up-to-date  community  does  all  of  these  things , 
itself,  thus  making  a  handsome  profit  on  the  business. 

Garbage  removal.  —  In  small  communities  garbage  may 
be  burned,  buried,  or,  better  yet,  fed  to  the  pigs ;  but  in 
larger  communities  where  pigs  cannot  be  kept,  the  garbage 
must  be  carefully  placed  in  covered  pails  and  put  out  for 
collection.  It  should  be  taken  up  once  a  day  in  hot  weather. 


The  use  of  a  bag  inside  the  rubbish  can  facilitates 
the  removal  of  waste. 


232 


DISPOSAL  OF   WASTES 


z.^-  . 


Most  large  communities  see  that  this  is  done.  The  gar- 
bage is  usually  collected  in  metal  carts  and  disposed  of  in 
several  ways.  One  of  the  best  methods  is  that  of  burning. 
Many  cities  now  own  their  own  incinerating  plants.  The 

city  of  Minneapolis 
requires  that  each 
day's  garbage  be 
wrapped  in  news- 
paper so  that  it  can 
be  burned  more 
readily.  Such  a  gar- 
bage disposal  plant 
usually  pays  for  it- 
self in  the  steam 
power  or  electricity 
generated.  Some 
cities  dump  their 
garbage  and  then 
bury  it,  but  this 
method  is  costly  and 
wasteful. 

Reduction  of  gar- 
bage. --  Another 
method  used  by 
New  York  and  other 
cities  is  the  reduc- 
tion method.  Gar- 


The  old  and  the  new  cart  for  collecting  garbage. 


bage  is  taken  by  means  of  scows,  or  in  wagons,  to  a  reduc- 
tion plant  where  bones  and  other  dry  waste  are  removed 
by  means  of  machinery.  The  organic  waste  is  then  heated 
from  eghit  to  ten  hours  under  a  high  steam  pressure,  and 
treated  with  chemicals ;  the  fats  are  extracted  from  it,  and 


HOW  WE  MAY  HELP  KEEP  THE  STREETS   CLEAN     233 

the  solid  matter  remaining  is  pressed  into  flat  cakes  and 
sold  for  fertilizers.  Fats  taken  from  garbage  by  this  process 
are  used  in  soap  and  perfumery  making,  and  all  of  the 
waste  matter  is  put  to  some  use  again.  The  plants,  al- 
though expensive  ones,  are  now  being  made  so  efficient 
that  they  more  than  pay  for  themselves. 

How  we  may  help  the  community  to  keep  the  streets 
clean.  —  Already  in  a  number  of  cities  boys  and  girls  have 
formed  Sanitary  Squads,  Civic  Leagues,  or  other  organiza- 
tions which  have  as  their  object  the  care  of  the  city  streets. 
The  Juvenile  Street  Cleaning  League  of  the  city  of  New 
York  has  a  membership  of  over  25,000,  most  of  whom  are 
boys  and  girls  in  the  elementary  schools.  Work  of  this 
nature  has  been  undertaken  by  a  similar  organization  formed 
in  one  of  the  large  city  high  schools.  Every  boy  and  girl 
should  have  the  best  interests  of  the  community  at  heart. 
Let  us  keep  garbage  pails  thoroughly  clean,  wash  them 
well  at  least  twice  a  week,  and  keep  them  covered,  thus 
helping  to  keep  down  the  fly  nuisance.  If  we  separate  ashes, 
paper,  and  tin  cans,  and  thus  obey  the  city  regulation,  we 
make  it  iust  that  much  easier  for  the  city  to  do  its  part  in 
cleaning  up.  But  most  of  all  we  need  to  remember  that  the 
streets  and  sidewalks  are  under  our  care.  If  we  throw 
fruit  peelings  or  scraps  of  paper  into  the  streets,  we  are 
selfishly  making  some  one  else  do  our  work.  If  we  go  on 
a  picnic  in  one  of  the  city  parks,  and  leave  the  remains  of 
our  lunches  with  scraps  of  paper  scattered  about  on  the 
ground,  we  are  doing  an  unfair  and  an  uncivic  thing. 
Remember  every  careless  act  makes  work  for  some  one. 
Refrain  from  spitting  in  the  streets ;  it  may  mean  death 
for  some  one.  Have  pride  in  your  city  and  help  make  it 
the  best  place  in  your  part  of  the  country  in  which  to  live. 


2J4 


DISPOSAL  OF   WASTES 


Scoring  our  community.  —  We  have  learned  enough 
about  flies  and  mosquitoes  to  know  the  harm  tnat  they 
are  capable  of  doing.  We  can  also  see  the  relation  be- 
tween these  pests  and  a  clean  community.  Let  us  be 
rigid  in  making  out  this  score.  If  it  is  low,  then  com- 
munity sentiment  ought  to  be  aroused  so  as  to  make  it 
better. 


SCORE  CARD.    PUBLIC  SANITATION 


PERFECT 

SCORE 

MY 

SCORE 

MOSQUITOES  AND  FLIES 

If  no  mosquitoes  (10)  ;  if  culex  only  (5)  ;  anopheles 

present  (o) 

If  no  flies  in  public  places,  in  stores,  on  street,  etc. 

(10)  ;   if  few  tii-s  (5)  ;   if  many  (o) 
An  effort  is  made  by  c  j/nmunity  to  destroy  mosquito 

breeding  places  (5) 
Public  inspectors  prsvent  fly  breeding  places,  as 
accumulations  of  stable  manure  (5) 

Interest   aroused   in   anti-fly   campaigns   or   anti- 

mosquito  campaigns  (5) 

35 

REMOVAL  OF  WASTE 

Garbage  removal  daily  in  hot  weather  (5);    twice 

weekly  (3)  ;   weekly  (o) 

Ashes  and  rubbish  collected  weekly  (5) 

Public  sewer  or  septic  tanks  used  (5) 

Sale  of  refuse  pays  the  city  in  part  at  least  for  its 

removal  (5) 

Vacant  lots  and  roadsides  well  kept  ;  free  from  weeds 

and  rubbish  (5) 

25 

STREETS 

Manure  and  litter  removed  twice  a  week  (5) 

Cleaned  by  wet  proczss.     Flushed  or  swept  while 

wet  (5) 

Dust  kept  down  by  frequent  sprinkling  or  by  oil  (5) 

15 

FOOD 

Restaurants  clean  and  inviting  ;  food  appetizing  (5) 
Have  paper  cups  at  soda  fountains  (5) 
Food  usually  eaten  unwashed  kept  in  stores  where 

it  cannot  be  handled  (5) 

Food  usually  eat-^n  unwashed  kept  in  stores  where 

customers  will  not  cough  or  sneez"  into  it  (5) 

Fruits  and  bakers'  foods  protected  from  dust  and 

flies  (5) 

25 

TOTAL 

100 

SCORING  OUR  COMMUNITY  235 

REFERENCE   BOOKS 

Baker  and  Ware,  Municipal  Government  of  New  York.     (Chapter  on  Water  Supply.) 

Ginn  and  Company. 

Brown,  Health  in  Home  and  Town.     D.  C.  Heath  and  Company. 
Dunn,  The  Community  and  the  Citizen.     D.  C.  Heath  and  Company. 
Folwell,  Sewerage.     (For  teachers.)     John  Wiley  and  Sons. 
Finch,  Everyday  Civics.  American  Book  Company. 
Gruenberg,  Elementary  Biology.     Ginn  and  Company. 
Hughes,  Community  Civics.     Allyn  and  Bacon. 
Hunter,  A  Civic  Biology.     American  Book  Company. 
Hunter,  Laboratory  Problems  in  Civic  Biology.     American  Book  Company. 
McCarthy,  et  al.,  Elementary  Civics.     Thompson,  Brown  and  Company. 
Municipal  Year-book.     City  of  New  York. 
Ogden  and  Cleveland,  Practical  Methods  of  Sewage  Disposal.     (For  teachers.)     John 

Wiley  and  Sons. 

Parsons,  Disposal  of  Municipal  Waste.     (For  teachers.)     John  Wiley  and  Sons. 
Venable,  Garbage  Crematories  in  America.     (For  teachers.)     John  Wiley  and  Sons 
Winslow,  Healthy  Living.     C.  E.  Merrill  Company. 

Wood,  Sanitation  Practically  Applied.     (For  teachers.)     John  Wiley  and  Sons. 
Ziegler  and  Jaquette,  Our  Community.     J.  C.  Winston  Company. 


CHAPTER   XVI 
STREET  LIGHTING 

Problems.  —  i.    To  learn  how  street  lighting  began. 

2.  To  learn  the  source  of  various  street  illuminants. 

3.  To  understand  the  processes  of  gas  manufacture. 

4.  To  understand  how  electricity  is  produced. 

5.  To  see  how  street  lighting  fixtures  may  beautify  rather 
than  mar  the  city  streets. 

Experiments.  —  i.   To  examine  some  of  the  products  resulting  from  the 
destructive  distillation  of  soft  coal. 

2.  To  compare  acetylene  with  city  gas  for  illumination. 

3.  To  see  how  an  electric  current  is  produced. 

4.  To  demonstrate  the  use  of  a  transformer. 

Project  I.  — To  MAKE  A  SURVEY  OF  STREET  LIGHTING  IN  A  SEC- 
TION OF  MY  COMMUNITY. 

1.  Select  a  section  that  includes  a  portion  of  the  business  dis- 
trict and  let  this  extend  to  the  residential  or  remote  part  of  the  city 
or  town,  preferably  to  your  own  neigh borhccd. 

2.  Make  a  plan  of  this  section  approximately  to  scale. 

3.  Determine  the  kind  of   lights  used  in  different  parts  of  the 
section.     Their    relative    strength.     Distance    apart    and    location. 
Show  all  this  on  the  diagram. 

4.  Determine  the  source  of  the  light  —  electric  or  gas,  and  make  a 
special  study  and  report  on  the  electric  or  gas  plant  which  supplies 
the  street  lights. 

5.  Compare  different  parts  of  this  section  in  regard  to  intensity 
of  illumination,  even  or  irregular  distribution  of  light,  and  judge 
whether  or  not  there  is  adequate  light  for  each  street,  considering 
its  use. 

236 


THE  HISTORY   OF  STREET  LIGHTING  237 

6.  Are  there  ugly  electric  light  poles  and  wires  in  any  streets? 
Where  do  you  find  ornamental  lamps  and  absence  of  wires  ? 

7.  Prepare  to  report  the  results  of  your  investigations  to  the 
class. 

Project  II.  —  MAKE  A  MODEL  GAS  PLANT  FOR  MANUFACTURING 
GAS  FROM  SOFT  COAL.  Demonstrate  it  to  the  class. 

Project  III.  —  MAKE  AN  ACETYLENE  GENERATOR  AND  LAMP  FOR 
HOME  USE.  Demonstrate  before  the  class. 

The  history  of  street  lighting.  —  Gas  and  electric  lights 
are  so  common  to  most  of  us  that  it  seems  as  if  cities  had 
always  been  lighted  in  this  way,  but  it  was  not  until  1415 
that  street  lights  were  introduced  into  London.  For  three 
hundred  years  householders  were  obliged  to  hang  lanterns 
in  front  of  their  houses  during  the  winter  evenings.  For- 
getful people  were  reminded  by  the  passing  watch  with 
these  words : 

Light  here,  maids,  hang  out  your  light, 
And  see  your  horns  be  clear  and  bright, 
So  that  your  candle  clear  may  shine 
Continually  from  six  to  nine, 

That  honest  men  may  walk  along, 
May  see  and  pass  safe  without  wrong. 

Street  lighting  began  in  this  country  when  New  York 
passed  a  law  in  1698  to  the  effect  that  every  seventh  house 
should  hang  out  a  light  on  the  end  of  a  pole.  Previous  to 
that  time  the  only  street  lights  were  those  that  shone  from 
the  houses.  Many  small  towns  in  Colonial  times  required 
citizens  to  keep  a  light  in  their  front  windows  until  certain 
hours  each  night.  In  the  latter  part  of  the  eighteenth 
century  London  was  well  lighted  with  oil  lamps  having 
wicks  and  glass  chimneys.  These  were  cared  for  by  the 
city.  Street  lighting  by  gas  was  introduced  in  England 


238 


STREET  LIGHTING 


A  night  scene  in  New  York  about  1698. 

in  1807,  and  in  this  country  in  1817,  when  Baltimore  in- 
stalled a  gas  plant  for  that  purpose. 

Chief  sources  of  street  lighting.  —  At  present  the  two 
principal  sources  of  artificial  light  for  city  streets  are  gas 
and  electricity.  In  some  rural  sections  we  still  find  oil 
lamps,  in  others  acetylene  is  used.  Many  sections  of  the 
country  are  favored  by  the  presence  of  natural  gas  near 
enough  to  have  the  supply  piped,  but  in  most  cities  arti- 
ficial gas  is  made  from  coal.  Both  natural  and  artificial 
gas  were  burned  as  bare  flames  until  within  recent  times, 
when  gas  mantles  were  introduced.  In  sections  where  gas 
is  used,  a  pilot  flame  is  often  left  burning  in  each  lamp 
during  the  day,  and  then  turned  on  at  night  causing  the 
entire  mantle  to  light  up.  The  competition  between  gas 
and  electricity  has  been  very  keen.  Both  have  been  much 
improved  of  late  in  methods  of  control  and  service  ren- 


THE  REASONS  FOR  LIGHTING  STREETS         239 

tiered.  During  this  period  of  competition  the  price  was  con- 
stantly reduced  until  the  greater  cost  of  coal  during  the  war 
caused  an  increase  in  the  cost  of  lighting  to  the  consumer. 
The  reasons  for  lighting  streets.  —  To  any  one  who  has 
traveled  through  a  well-lighted  district  and  a  poorly  lighted 
one  the  reasons  for  street  lighting  are  very  apparent.  Good 
lighting  results  in  increased  traffic,  increased  trade  in  the 


A  well-lighted  street. 

stores,  increase  in  property  value,  decrease  of  crime,  and 
decrease  in  accidents.  Industrial  accidents  are  shown  to 
increase  during  the  season  of  short  daylight  when  more  work 
is  done  under  poorly  lighted  conditions.  Street  accidents 
increase  for  the  same  reason,  more  accidents  occurring  in 
poorly  lighted  streets.  An  up-to-date  community  demands 
better  lighted  streets;  more  light  without  objectionable 
glare,  since  in  these  days  of  strong  auto  headlights  this 
removes  the  necessity  of  using  such  headlights  in  a  city. 


240 


STREET  LIGHTING 


Ci/ftB 


cuffg 


What  constitutes  good  street  lighting.  —  Good  street 
lighting  means  soft  and  cheerful  lighting  with  absence  of 
glare.  Lights  must  be  placed  close  enough  so  that  there 
are  no  dark  recesses  and  no  objectionable  shadows.  Re- 
flectors which  spread  light  in  ovals  instead  of  in  circles 
along  the  street  give  greater  efficiency  and  effectiveness 
in  lighting.  In  the  small  community  we  frequently  lind 
lights  not  turned  on  while  the  moon  is  up,  but  all  large 
.  _  .  cities  now  have  an 

all-night  system. 
This  calls  for  about 
4000  actual  hours 
of  lighting  per  year 
from  each  lamp. 

Lighting  by  nat- 
ural gas.  —  Natural 
gas  is  obtained  by 

Hrillino1  in  rrmrh   HIP 
mS  U 

same  way    as  they 

drill  for  oil,  and  it  is  found  closely  associated  with  oil. 
Frequently  in  drilling  for  oil  natural  gas  is  found  instead. 
West  Virginia  is  the  greatest  natural-gas-producing  state. 
Cities  more  than  one  hundred  miles  distant  from  the  wells 
are  supplied  with  gas  for  one  -fourth  as  much  as  artificial 
gas  costs.  Natural  gas  can  be  used  without  any  purifying, 
but  smce  the  high  price  of  gasoline  it  is  robbed  of  its  gaso- 
line contents  before  it  is  distributed  through  the  gas 
mains. 

Manufacturing  artificial  gas.  —  Gas  for  street  lighting  is 
usually  manufactured  by  one  of  two  methods  :  either  by 
the  process  of  destructive  distillation  of  coal  or  by  what  is 
known  as  the  water-gas  method.  Since  the  use  of  gas 


Are  there  dark  areas  between  the  street  lamps  in  your 
town?     Compare  streets  A  and  B  above. 


HOW  COAL  GAS  IS  MANUFACTURED 


241 


mantles  for  street  lighting,  both  kinds  of  gas  are  frequently 
produced  in  the  same  plant,  and  are  mixed  in  the  mains 
for  use  with  the  mantle  lamps. 

Experiment.  —  To  examine  some  of  the  products  resulting  from   the  de- 
structive distillation  of  soft  coal. 

Materials:  Soft  coal,  red  litmus  paper,  filter  paper,  lead  nitrate  or  lead 
acetate,  limewater,  hard  glass  test  tube,  and  collecting  bottles. 

Method:  Set  up  apparatus  as  in  figure.  A  is  a  hard  glass  test  tube  con- 
taining coarsely  ground  soft  coal  f  full.  B  is  an  empty  bottle.  C  is  a 


bottle  holding  (i)  a  piece  of  filter  paper  moistened  with  lead  nitrate 
or  acetate  solution,  and  (2)  a  piece  of  moist  red  litmus  paper.  D  con- 
tains limewater.  E  is  a  wide-mouth  gas-collecting  bottle.  Place  the 
litmus  paper  as  near  as  possible  to  the  mouth  of  the  inlet  tube  in  C. 
Heat  the  hard  glass  test  tube  gently  at  first,  and  when  thoroughly 
warmed  increase  the  heat,  using  two  flames  if  possible.  Look  for  any 
change  in  the  litmus  paper.  This  does  not  always  occur  even  when  the 
experiment  is  carefully  performed,  as  the  temperature  condition  for 
driving  off  a  sufficient  amount  of  ammonia  is  difficult  to  attain.  An 
acid  turns  blue  litmus  red  and  an  alkali  turns  red  litmus  blue.  Hydro- 
gen sulphide,  an  impurity  in  the  gases  from  coal,  turns  lead  nitrate  or 
acetate  black.  Collect  two  bottles  of  gas  after  all  the  air  has  been  driven 
out  of  the  apparatus. 

Results:  Determine  if  the  gas  will  burn.  Describe  and  name  the  product 
in  A.  Note  the  properties  of  the  matter  in  B.  Account  for  any 
change  in  the  two  papers  in  C.  Explain  the  change  in  D.  Give  the 
commercial  name  of  the  gas  collected  in  E.  What  substances  identi- 
fied are  of  importance  commercially  ? 

How  coal   gas   is  manufactured.  —  In   the   process   of 
destructive  distillation  of  coal  the  complex  substances  of 

H.  W.  CIV.  SCI.  COMM. l6 


242 


STREET  LIGHTING 


Gas  holders  where  millions  of  cubic  feet  of  illuminating  gas  are  stored. 


the  coal  are  broken  up  into  simpler  substances  by  the  heat, 
arid  many  of  the  resulting  gaseous  products  are  condensed. 
Illuminating  gas,  the  main  product  of  this  process,  is  not 
condensed  and  after  being  purified  is  ultimately  stored  in 
the  gas  holder.  Bituminous  coal,  which  contains  from  30 
to  40%  of  volatile  matter,  is  heated  in  iron  retorts.  This 
volatile  matter  is  driven  out  at  a  temperature  of  about 
800°  Fahrenheit.  In  making  gas  a  ton  of  coal  produces 
on  an  average  two-thirds  of  a  ton  of  coke,  13  gallons  of 
tar,  20  pounds  ammonium  sulphate  and  12,000  cubic  feet 
of  gas.  The  by-products  obtained  from  the  coal  tar  are 
far  more  valuable  than  the  gas  or  coke  obtained.  Such 
substances  as  aniline  colors,  light  and  heavy  oils,  carbolic 
acid,  and  naphthalene  flakes  are  some  of  the  products  thus 
obtained. 


WATER  GAS 


243 


Steps  in  the  process  of  the  manufacture  of  coal  gas.  - 

Soft  coal  is  placed  in  the  retort,  and  in  the  process  of  heat- 
ing is  turned  into  coke.  Tne  gases  and  by-products  pass 
off  into  what  is  known  as  a  hydraulic  main.  In  the  hy- 
draulic main  some  of  the  tar  is  condensed  and  disposed  of, 
still  more  of  it  being  taken  out  a  little  later  by  what  is 
known  as  the  tar  extractor.  The  gases  are  then  forced 
through  a  spray  of  cold  water  in  condensers  and  scrubbers 
by  means  of  which  the  ammonia  and  other  by-products 
are  removed.  After  the  gas  has  been  purified  it  is  passed 
to  the  huge  tank  or  holder,  which  is  a  familiar  blot  on  the 
landscape  of  so  many  cities.  From  this  holder  it  is  passed 
out  through  the  city  mains  and  distributed  to  the  street 
lights  and  to  the  homes,  where  it  is  used  for  cooking,  light- 
ing, and  heating  purposes. 

Water  gas.  —  Water  gas  is  often  made  in   the   same 
plant,  and,  as  we  have  said,  is  mixed  with  ordinary  coal  gas 


GasGfeneixttop  Superheater 


Manufacture  of  city  gas,  combining  coal  gas  and  water  gas. 


244 


STREET  LIGHTING 


for  purposes  of  street  lighting  and  home  use.  It  is  made 
by  passing  steam  under  pressure  through  incandescent 
hard  coal  or  coke.  The  gases  pass  off  into  a  structure 
called  the  carburetor.  Here  coal  oil  is  sprayed  into  the  gas. 
It  then  passes  to  the  superheater,  where  it  is  changed  to  a 
permanent  gas  which  will  burn.  It  is  cheaper  to  make  water 
gas  than  coal  gas,  but  without  extensive  enriching  with  oil  it 
is  not  suitable  for  lighting  unless  mantles  are  used.  A  third 
kind  of  gas  called  "  producer  gas  "  is  made  in  some  plants 
for  fuel  purposes  only. 

Experiment.  —  To  compare  acetylene  with  city  gas  for  illumination. 

Materials:    An  8-ounce  bottle  with   i-hole  stopper  to  fit.      Acetylene 

burner  tip.     Ordinary  gas  tip.     Calcium  carbide. 

Method:  Fill  the  8-ounce  bottle  with  illuminating  gas.  Apply  a  match 
to  the  gas.  Observe  whether  it  burns  with  much  or  little  luminosity 
and  black  smoke. 

Pour  25  c.c.  of  water  into  the  8-ounce  bottle.  Drop  a  small  lump 
of  calcium  carbide  into  it.  Light  the  gas  at  the  mouth  of  the  bottle. 
Compare  luminosity  and  smoke  with  result  when  city  gas  was  burned. 

Connect  the   acetylene    burner 


tip  to  a  tube  passing  through 
the  rubber  stopper.  Drop  a 
lump  of  calcium  carbide  into 
water  in  the  bottle.  Close  the 
bottle  with  the  stopper.  After 
a  couple  of  minutes,  light  the 
gas  issuing  from  the  burner. 
Light  the  city  gas  issuing  from 
the  ordinary  gas  tip.  Compare 
the  two  flames  for  whiteness  and 
intensity  of  light. 

Results  :  What   are   the   results    of 
these  experiments? 


An  acetylene  generator  is  easily  made 
from  a  tin  can  and  a  medicine  dropper. 


Acetylene     lighting. - 

Acetylene  is  so  rich  in  carbon 
that  it  gives  a  brilliant  white  light  when  burned  freely  with- 
out anv  mantle.  A  much  smaller  volume  of  gas  is  needed  for 


ELECTRICITY  FOR  STREET  LIGHTING 


245 


a  given  intensity  of  b'ght  than  where  natural  or  coal  gas  is 
used.  The  equipment  for  manufacturing  enough  gas  to 
light  a  small  village  or  factory  is  much  less  expensive  than 
required  to  manufacture  coal  or  water  gas.  Acetylene  gas, 
however,  is  more  expensive  than  the  other  types  of  gas  when 
they  are  made  in  a  large  plant. 

Electricity  for  street  lighting.  —  We  have  already  seen 
that  electricity  can 
be  made  more 
cheaply  where  there 
is  water  power.  The 
energy  locked  up  in 
water  falling  from 
a  height  turns  tur- 
bines or  water  wheels 
which  in  turn  oper- 
ate a  generator  and 
make  electricity. 

Falling      Water      has  Energy  of  falling  water  changed  to  light. 

mechanical      energy 

which  is  changed  to  electrical  energy.     This  is  an  illus- 


the  changes  in  energy  suggested  above. 


tration  of  the  law  of  the  transformation  of  energy.     This 
law  is  equally  well  shown  when  electricity  is  produced  from 


246 


STREET  LIGHTING 


coal.  Coal  is  burned  in  a  furnace  under  a  boiler.  Steam 
from  the  boiler  makes  the  wheels  of  a  steam  engine  revolve. 
The  steam  engine  in  turn  rotates  the  armature  of  a 
dynamo  and  electricity  results.  How  many  changes  in 
energy  are  there  in  producing  electricity  from  coal? 
Barges  or  cars  bring  to  the  plant  tons  upon  tons  of  stored 
energy  in  the  coal  from  which  a  little  later  electricity  flows 
out  through  insulated  wires  to  light  every  nook  and  cor- 
ner of  the  city. 


Experiment.  —  To  see  how  an  electric  current  is  produced. 
Materials:  A  coil  of  wire.     A  strong  bar  magnet,  a  galvanometer.     Con- 
necting wires. 

Method  and  Results:  Connect  the  ends  of  the  wire  forming  the  coil  to  the 

galvanometer,  thus  making  a 
"  closed  coil."  Move  the 
magnet  in  line  with  the  axis 
of  the  coil  down  into  the 
coil.  Quickly  withdraw  the 
magnet.  Observe  the  gal- 
vanometer needle  in  each 
case.  Hold  the  magnet  still 
inside  the  coil.  What  result? 
Conclusion:  The  movement  of 
the  galvanometer  needle  is 
due  to  a  current  of  electricity. 
The  magnet  always  is  sur- 
rounded by  lines  of  magnetic 

force.    Under  what  conditions  of  coil  and   magnet   does    a    current 
result  in  the  coil? 

Application:  Similar  relations  between  closed  coils  and  magnetic  lines 
of  force  exist  in  the  dynamo.  Can  you  tell  how  it  is  then  that  a  dynamo 
produces  electricity? 

How  electricity  is  produced.  —  When  a  closed  coil  of 
wire  is  moved  across  the  lines  of  force  in  a  magnetic  field  a 
current  of  electricity  is  produced.  The  dynamo  is  a  de- 


ALTERNATING  CURRENT  AND  DIRECT  CURRENT  247 


vice  which  produces  this  current.  It  has  an  electromagnet 
by  means  of  which  a  powerful  magnetic  field  may  be  pro- 
duced. Between  the  poles  of  tne  dynamo  an  armature 
consisting  of  many  coils  of  wire  is  rotated.  The  two  ends 
of  each  coil  of  wire  terminate  in  the  commutator  con- 
sisting either  of  a  pair  of  metal  rings  or  of  segments  sepa- 
rated by  insulated  material.  As  the  commutator  revolves 
it  touches  fixed  strips  of  conducting  material  known  as  the 
brushes.  Wires  which  carry  the  electricity  away  to  do 
its  work  are  attached  to  the  brushes.  Some  dynamos  have 


•'Ring' 
Com  mutolor 


Alternating  Current 


Direct  Current/ 


A  simple  diagram  to  show  the  principle  of  the  dynamo.  Lines  of  magnetic  force  fill 
the  space  between  the  ends  of  the  magnets  N  and  S.  As  the  coil  of  wire  is  rotated 
in  this  space  electricity  is  generated  in  the  wire.  When  distributed  just  as  pro- 
duced, an  alternating  current  (A.  C.)  results,  but  when  a  segmented  commutator 
is  used,  a  direct  current  (D.  C.)  results  in  the  outside  circuit. 

a  revolving  magnetic  field  and  a  fixed  armature,  but  the 
principle  of  producing  electricity  is  the  same.  There  is 
always  relative  motion  between  the  magnetic  field  and  the 
coil  of  wire.  The  dynamo  is  also  called  a  generator. 

Alternating  current  and  direct  current.  —  As  one  side  of 
the  wire  coil  of  the  armature  passes  the  north  pole  of  the 
magnet  a  current  results  in  a  certain  direction.  As  it  passes 
a  south  pole  the  current  is  produced  in  the  opposite  direc- 
tion, thus  in  every  revolution  of  a  coil  of  wire  between 
two  magnetic  poles  two  currents  of  electricity  are  produced. 


248  STREET  LIGHTING 

As  the  coil  continues  to  revolve  the  current  is  alternating  : 
going  first  in  one  and  then  in  the  opposite  direction.  This 
current  is  called  from  its  change  of  direction,  an  alter- 
nating current.  The  alternating  current  is  taken  off  by 
brushes  in  contact  with  a  ring  commutator.  If,  however, 
a  segmented  commutator  is  used  the  brushes  take  off  a 
direct  current  of  electricity.  Just  how  this  is  done  will  be 
explained  when  you  study  physics.  Either  a  direct  cur- 
rent (D.  C.)  or  alternating  current  (A.  C.)  may  be  used 
with  incandescent  lamps  but  as  a  rule  the  direct  current  is 
preferred  for  arc  lights. 

Use  of  transformers. -- Transformers  are  devices  used 
for  "  stepping  up  "   or    "  stepping   down  "    the   voltage, 


£l£CTfi/C/TY  P00DUCID  M£#E  £LECTR/C/rr  CONSUMCD  *T  W*  PMSSUfft 

POtVEH/S  CH£Af>  /N  OVff  HOMfS  AND  fACTOff/CS 

The  use  of  transformers  in  a  system  of  distribution  of  electrical  energy. 

When  a  large  current  of  electricity  is  carried  a  long  dis- 
tance there  is  a  very  great  loss  of  energy  due  to  the 
heating  of  the  conducting  wires.  When  electricity  is 
carried  the  long  distance  at  a  high  voltage  and  correspond- 
ingly low  current,  there  is  little  heating  effect  and  so  only 
a  small  loss  of  electrical  energy  results.  The  transformer 
makes  it  possible  to  carry  electricity  at  high  voltages  and 
to  step  it  down  just  before  it  is  used.  A  direct  current 


ARC  LIGHTS 


249 


cannot  be  changed  by  the  use  of  the  transformer  to  a 
different  voltage,  but  the  alternating  current  can.  For 
this  reason  electric  light- 
ing circuits  usually  have 
the  alternating  current. 


Gurrerct^ 


L,ow  voltage 
bell. 


Experiment.  —  To  demonstrate 
the  use  of  a  transformer. 
Materials:    Two  bell  trans- 
formers for  changing  115 
V.  to  6V.,  12  V.,  and  18 
V.    An    A.  C.    voltmeter 
reading  to  130  volts.  Wire. 
Method  and  Results:    Meas- 
ure  the   voltage    of    the 
A.    C.    electric  light    cur-    How  can  three  different  voltages  be  produced  tf 


rent. 


there  are  only  two  separate  secondary  coils? 


(a)  Connect  the  transformer  to  the  lighting  circuit.    Measure  the 
voltage  obtained  in  each  of  the  three  secondary  circuits.     Results? 

(b)  Connect  two  binding  posts  of  the  secondary  circuit  of  one  trans- 
former to  the  two  corresponding  binding  posts  of  the  other  transformer. 
Connect  the  primary  of  one  to  the  lighting  circuit  and  what  would 
ordinarily  be  the  primary  of  the  second,  but  which  as  now  used  is  a 
secondary  to  the  voltmeter.     Result?    How  do  you  account  for  the 
result? 


Types  of  electric  lamps.  —  There  are  two  types  of  elec- 
tric lamps  used  for  street  lighting,  the  arc  lamp  and  the 
incandescent,  and  there  are  many  forms  of  each  type. 
The  arc  lamps  are  usually  of  much  greater  candle  power 
than  are  the  incandescent,  but  the  arc  lamps  require  a 
great  deal  of  care  to  keep  the  carbons  adjusted,  and  the 
carbons  must  be  replaced  frequently.  The  incandescent 
lights,  because  of  their  smaller  candle  power,  must  be 
placed  closer  together.  They  require  no  attention  except 
renewal  when  one  burns  out. 

Arc  lights.  —  When  an  electric  circuit  is  closed  by  the 


250 


STREET  LIGHTING 


contact  of  two  carbon  pencils,  great  heat  is  generated  by  the 
resistance  at  the  point  of  contact.  Carbon  at  the  point 
of  contact  becomes  vaporized  and  if  the  carbons  are  drawn 
a  short  distance  apart  this  vaporized  carbon  continues  to 
carry  the  current  of  electricity.  Inasmuch  as  this  stream 
of  highly  heated  vapor  usually  bends  out  in  the  form  of  an 
arc,  this  is  called  an  arc  light.  When  pure  carbon  pencils 
are  used  the  points  of  the  pencils  are  intensely  lighted 
but  the  arc  itself  gives  very  little  light.  In  order  to  in- 
crease the  amount  of  light  in 
the  arc  a  core  containing  cal- 
cium salts  is  made  in  the  carbon. 
This  gives  a  brilliant  yellow  arc 
known  as  the  "flaming  arc"  If 
the  carbons  are  replaced  by  a 
heavy  copper  rod  (upper)  and 
a  tube  of  magnetite  (lower)  a 


WrxicK  i5 


The  inclosed  electric  arc  used  in  street  brilliant     magnetite     WC     results. 

Both  of  these  luminous  arcs  are 

used  in  street  lighting.  Inclosed  rather  than  open  arc 
lights  are  now  almost  always  used  because  they  require 
less  attention. 

Incandescent  lights.  —  The  most  important  use  of  the 
heat  factor  of  an  electrical  current  is  in  the  heat  of  the  fila- 


5OOO  Voi^TS 


DYNAMO 


Lamp  99        Lcmp  98        Lamp  97         Lon\p  9G 


Arc  lamps  are  connected  in  series. 


HOW  ELECTRICITY  IS  SENT  TO  CONSUMER     251 


ments  of  incandescent  lamps  to  produce  light.  The  larger 
tungsten  lamps  run  from  one  hundred  to  five  hundred  or 
more  candle  power,  and  are  in  common  use  for  street 
lighting.  These  lamps  are  gradually  replacing  the  arc 
lights  in  many  cities. 

Lamp  circuits.  —  When  arc  lights  are  used,  the  lamps 
are  placed  in  series,  each  lamp  taking  about  fifty  volts. 
A  circuit  with  one  hundred  lamps  would,  therefore,  require 
5000  volts.  Incandescent  lamps,  on  the  other  hand,  are 


-o 
-o 


-o 
o 


-o 

-o 
-o- 


Incandescent  lamps  are  connected  in  parallel. 

connected  in  parallel.    A  i  lo-volt  circuit  would  be  sufficient 
for  any  number  of  lamps  so  joined. 

How  electricity  is  sent  to  the  consumer.  —  A  few  years 
ago  it  was  a  common  sight  to  see  the  streets  of  cities 
disfigured  by  huge  poles  bearing  many  wires.  To-day  in 
well-regulated  communities  all  telephone  and  electric  light 
wires  are  placed  in  conduits  underground.  In  large  cities 
they  may  be  placed  in  one  large  pipe  gallery.  In  other  places 
vitrified  tiling  is  used  in  which  to  run  the  wires,  but  it  is 
quite  expensive.  The  use  of  underground  cables  instead 
of  overhead  wires  is  a  great  advantage.  We  have  no  trouble 
from  broken  wires  in  storms,  less  danger  to  people  and  more 
beautiful  streets.  While  the  first  installat;on  is  expensive, 
the  wires  are  so  well  protected  that  they  last  much  longer, 


252 


STREET  LIGHTING 


and  the  final  cost  of  underground  cables  is  not  much 
greater  than  that  of  the  overhead  system  of  wiring. 

Beauty    a    detail     in 
street  Hghting.  —  While 
utility  is  the  first   con- 
sideration in  street  light- 
ing, yet  the  modern  com- 
munity   must     consider 
beauty  as   well.      Orna- 
mental   fixtures,    reflec- 
tors,   and     globes    cost 
but     little     more     than 
ugly  ones,  and  it  may  be 
that  for   the   added  at- 
tractiveness they  give,  a 
city  will    eventually   be 
repaid     in     a     financial 
way.     There  is  no  doubt 
but  that  they  pay  in  the 
satisfaction  they  give  to 
one's     aesthetic     sense. 
Compare  the  street  of  a 
few  years   ago   with   its 
crooked     posts     and     a 
large  arm  with  its  pulley 
cord    and    loose    wires, 
with  the  street  of  to-day 
where  ornamental  stand- 
ards     have    the    group 

Electric  street  lamp  showing  wiring.     Method       SVStem    of    lighting     With 

underground    wires.     In 
many  towns  the  value  of  property  along  certain  streets 


BEAUTY  A  DETAIL  IN  STREET  LIGHTING       253 

has  been  increased  50%  by  the  introduction  of  adequate 
and  ornamental  street  lights. 


Utility  lighting  vs.  ornamental  lighting. 


REFERENCE  BOOKS 

Articles  on  Street  Lighting.    The  American  City,  New  York. 

Barber,  First  Course  in  General  Science.    Henry  Holt  and  Company. 

Brownlee,  et  al.,  Chemistry  of  Common  Things.    Allyn  and  Bacon. 

Blanchard  and  Wade,  Foundations  of  Chemistry.    American  Book  Company. 

Dunn,  The  Community  and  the  Citizen.     D.  C.  Heath  and  Company. 

Hodgdon,  Elementary  General  Science.     Hinds,  Hayden  and  Eldredge. 

Hughes,  Community  Civics.     Allyn  and  Bacon. 

Lecture  8,  Evolution  of  Street  Lighting.     General  Electric  Lecture  Service,  Sche 

nectady,  New  York. 

McPherson  and  Henderson,  Elementary  Study  of  Chemistry.     Ginn  and  Company. 
Municipal  Year-book.     City  of  New  York. 
Ziegler  and  Jaquette,  Our  Community.    J.  C.  Winston  Company. 


CHAPTER  XVII 

HOW  THE  COMMUNITY  SAFEGUARDS  LIFE  AND 
PROPERTY 

Problems.  —  i.  To  learn  the  various  duties  of  the  police 
force. 

2.  To  understand  the  value  of  law  and  order. 

3.  To  understand  how  the  fire  apparatus  "  works." 

4.  To  see  the  value  of  heeding  traffic  regulations  and  fire 
regulations. 

5.  To  understand  the  relation  of  various  city  departments 
in  the  promotion  of  safety  for  cUizens. 

Experiments.  —  i.   To  see  how  the  force  pump  works. 
2.   To  demonstrate  the  automatic  sprinkler. 

Project  I.  —  To  FIND  OUT  ALL  THE  TRAFFIC  REGULATIONS  OF  MY 

COMMUNITY. 

Project  II.  —  To  STUDY  THE  FIRE  EQUIPMENT  AT  A  NEAR-BY  FIRE 

STATION. 

1.  By  personal  visits  learn  the  different    pieces  of  apparatus. 
List  them. 

2.  Find  out  the  purpose  of  each  and  how  it  is  used. 

3.  Find  out  the  method  of  operation  of  the  extinguishing  pumps, 
engines,  and  signal  devices. 

4.  Report  on  these  and  other   interesting  things  which  can  be 
learned  by  conversation  with  the  firemen. 

Two  important  city  departments.  —  Two  of  the  most 
important  departments  of  a  city  are  the  police  and  fire 
departments.  None  but  anarchists  want  to  live  in  a  com- 

254 


A  MODERN  POLICE  SYSTEM  255 

munity  given  over  to  lawlessness,  and  even  anarchists 
believe  in  protection  against  fire  unless  it  be  used  by  them 
as  a  weapon  against  good  government.  We  are  apt  to 
think  of  the  police  in  a  community  having  as  their  sole 


Modern  fire  apparatus  in  service. 

duty  the  care  of  that  small  group  of  people  who  do  not  re- 
spect the  rights  of  others,  but  this  is  far  from  being  their 
only  duty. 

A  modern  police  system.  —  The  city  of  New  York 
has  an  army  of  police  of  somewhat  over  ten  thousand  men. 
These  policemen  are  divided  into  a  number  of  squads. 
Certain  men,  called  patrolmen,  have  charge  of  the  law  and 


256      HOW  THE   COMMUNITY  SAFEGUARDS  LIFE 

order  on  the  streets  of  the  city.  Another  squad  patrols 
the  harbor,  using  over  a  dozen  boats  for  this  purpose. 
Another  squad  has  charge  of  the  violation  xof  the  motor 
vehicle  laws.  Still  another  squad  inspects  the  steam  boilers 
in  various  parts  of  the  city,  while  a  separate  squad  makes 
up  the  bureau  of  criminal  identification.  This  has  charge 
of  the  "  rogues'  gallery "  with  its  systems  of  measure- 
ments, its  criminal  records,  and  its  finger  print  system. 
This  bureau  also  conducts  a  school  for  detectives.  Besides, 
there  is  a  headquarters  building  with  its  squad  of  officials 
whose  business  it  is  to  direct  the  entire  police  sys- 
tem. 

The  police  patrol   signal   system.  —  The  police  head- 
quarters in  city  districts  have  a  signal  system  which  is 


Police  signaling  desk  at  headquarters. 


electrically  equipped  so  that  it  registers  approximately 
the  location  of  every  police  patrolman  at  any  time  and 
makes  it  possible  to  hold  a  telephone  conversation  with 
him  whenever  he  reaches  the  police  signal  station  from 


LAW  AND   ORDER 


257 


which  he  sends  word  of  his  presence.  There  is  a  double 
advantage  in  this  system.  The  patrolman  can  easily  send 
messages  to  headquarters  with  little  delay.  The  line  is 
never  "  busy  "  but  is  always  open  for  his  message.  Head- 
quarters can,  within  a  short  time,  reach  any  patrolman 
if  it  is  necessary  to  send  him  a  message.  This  signal 
system  more  than  doubles  the  efficiency  of  the  police  de- 
partment. 

Law  and  order.  —  When  a  group  of  people  live  together 
in  a  community  each  individual  has  certain  rights  which 
must  be  respected  by  the  others.  There  is  considerable 
difference  in  the  way  different  individuals  who  insist  upon 
their  own  rights  accept  the  restrictions  of  their  own  ac- 
tions. In  most  communities  there  are  likely  to  be  some 
people  who  insist  upon  violating  the  rights  of  others  when 
any  opportunity  offers.  It  is  to  the  advantage  of  every 
community  to  be  governed  by  national  and  state  laws  and  in 
addition  by  the  regu- 
lations of  the  city 
or  community.  For 
this  purpose  we  have 
in  the  community  the 
police  and  a  system 
of  courts.  In  seri- 
ous discord  such  as 
strikes  and  riots,  the 
officers,  the  militia,  or 
even  the  army  and 
navy  may  be  called 
upon  for  assistance, 
but  under  ordinary  circumstances  the  police  can  effectively 
maintain  law  and  order  within  the  comumnity. 

H.   W.   CIV.   SIC.   COMM. 17 


A  traffic  officer. 


258     HOW  THE  COMMUNITY  SAFEGUARDS  LIFE 

Work  of  the  patrolmen.  —  A  good  many  years  ago  the 
policeman  was  a  sworn  enemy  of  the  small  boy  of  the 
community,  but  now  the  small  boy  has  learned  to  know  him 
better.  Not  only  do  the  kindly  patrolmen  make  it  pos- 
sible for  us  to  pass  safely  to  school  in  the  morning,  but  they 
also  help  other  people  to  keep  safe  on  the  streets.  The 


.DIVISION 

POLICE  DEPARTMENT 

CITY  CF    INDIANAPOLIS 

DIST.  NO.   1 

DIVISION 

POLICE  DEPARTMENT 

CITY  OF    INDIANAPOLIS 

DIST.  NO. 

PATROLMAN'S  REPORT 
!>.(« 

PATROLMAN'S  REPORT 

19 

To  the  Board  of  Health  through  the  official  channels  of  the  Police  Dept  . 

Al  M.  I  observed  the  folio*  ing  condition  and  took  the  action  noted 
Location                                                                                                    | 

To  the  Board  of  Works  through  the  official  channel,  of  the  Police  Dept. 
At-  M.  I  observed  the  following  condition  and  look  the  action  noted 
Location 

IniiUtarv  A 

lev. 

Broken  Curb  Stone 

Broken  Electric  Wire 

lM.nitarv  Bickjard 

Broken  Manbc 

le  Cover 

Bagging  Electric  Wire 

Insanitary  Garbaje  Cans 

Broken  Sidewalk 

Broken  Street  Lamp 

Insar.itarj  Vaults 

Defective  Bridge  Culvert 

Leaking  Gas 

Orsrcrowded  Houses 

Defective  Sewi 

r  Catch  Basin 

Leaking  Hvdrant 

Improper  Vei 

tilatlon  of  Public  Buildings 

Hole  in  Street 

Broken  Water  Main 

Food  Unprotected  from  Dirt  and  Flies 

Street  Opening  not  Repaved 

Unclean  Street-Gutters 

REPORT 

HERE  ANT  OTHER  MATTER  NOT  LISTED 

REPORT  HERE  ANT  OTHER  MATTER  NOT  LISTED 

Action  Taken 

Action  Taken 

(Rank)                     (Signature)                      (Badge  No.) 

BLANK  FOR  PATROLMAN'S  REPORT 
TO  BOARD  OF  HEALTH 

(Rank)                   (Signature)                     (Badge  No.) 
P.D.511 

PATROLMAN'S  REPORT  BLANK  FOR 
RECORDING  CONDITIONS  FOR 
ATTENTION  OF  BOARD  OF  WORKS 

Blanks  for  patrolmen's  reports. 


little  boy  or  girl  who  is  lost  instantly  goes  to  the  big 
patrolman  on  the  corner  to  find  the  way  home.  The 
stranger  within  the  city  asks  his  way  to  this  or  that  place. 
The  patrolmen  regulate  traffic  on  the  busy  streets.  They 
keep  crowds  back  when  parades  are  moving  through  the 


SAFE  AND  SANE  DRIVING  259 

streets,  and  of  course,  at  all  times  they  are  the  servants 
of  the  people.  It  is  their  duty  to  take  offenders  against 
law  and  order,  to  protect  property  against  theft,  and  to 
protect  our  lives  against  violence.  The  police  department 
of  a  city  works  with  the  sheriff  of  a  county  and  his  depu- 
ties, and  in  times  of  danger  the  police  department  has  a 
right  to  call  upon  private  citizens  to  give  aid  in  the 
maintenance  of  law  and  order. 

The  patrolman  in  the  city  police  department  is  also  an 
inspector  of  the  general  conditions  of  the  streets,  of  de- 
fective sewers,  broken  electric  wires,  broken  street  lamps, 
leaking  gas  mains,  leaking  hydrants,  broken  water  mains, 
and  has  many  other  duties  which  we  should  not  guess. 
The  records  which  are  turned  in  by  the  police  have  to  be 
models  in  accuracy  and  in  detail,  and  after  having  seen 
such  a  record  we  should  certainly  have  more  respect  for 
the  duties  which  these  men  have  to  perform.  In  the  city  of 
New  York  the  police  at  the  present  time  have  an  aviation 
force,  and  during  the  World  War  they  were  prepared  to  cope 
with  any  emergency  that  might  arise  from  bombing  by  a 
hostile  air  force. 

Prevention  of  accidents.  —  Traffic  police  officers  are  the 
greatest  factor  in  the  prevention  of  accidents.  Almost 
as  many  thousands  of  American  people  were  killed  in  the 
United  States  during  the  World  War  from  accidents  as 
were  killed  in  France.  It  is  not  merely  in  the  street  traffic 
that  there  is  very  great  danger,  but  street  cars  and  railroad 
grade  crossings,  fallen  electric  wires,  unguarded  excava- 
tions, unsafe  railings,  and  icy  sidewalks  and  pavements 
all  add  their  quota  to  the  list  of  accidents. 

Safe  and  sane  driving.  —  No  regulations  and  no  officers 
can  prevent  accidents  which  are  invited  by  the  recklessness 


260     HOW  THE   COMMUNITY   SAFEGUARDS  LIFE 

or  carelessness  of  drivers.  Fortunately,  since  police  regu- 
lations are  strict  within  cities,  most  drivers  heed  traffic 
regulations  fairly  well.  Careful  drivers  seldom  get  into 
trouble.  They  cannot,  however,  escape  from  danger  into 
which  they  are  forced  by  the  careless  driver.  It  is  only  right 


Wreck  of  the  reckless  driver. 

that  the  careless  driver  should  lose  his  license,  as  he  is  a  men- 
ace to  the  community  as  long  as  he  is  allowed  to  drive  a  car. 
The  equipment  of  a  fire  department.  —  Most  of  us  have 
enjoyed  a  visit  to  the  fire  station.  The  wide  open  doors, 
the  shining  brass  of  the  engines  and  trucks,  the  stall  where 
motor  apparatus  has  replaced  the  intelligent-looking 
horses,  and  the  brass  pole  from  the  upper  story  where  the 
firemen  slide  down  when  hurrying  to  a  fire,  have  all  left 
their  impressions  upon  us.  The  complicated  system  of 
fire  signals  has  always  interested  us,  and  perhaps  we  may 


FIRE  ENGINES 


261 


have  been  fortunate  enough  to  have  been  in  the  building 
when  an  alarm  was  rung  in.     Then  we  remember  the  visit 


A  fire  station  on  a  corner  lot. 


to  the  upper  part  of  the  fire  house  where  the  sleeping 
quarters  and  the  social  rooms  are  located. 

The  engines.  —  In  most  fire  departments  we  find  two 
kinds  of  engines,  the  "  chemical  "  and  the  "  steamer." 
The  "  chemical  "  is  usually  the  first  to  arrive  at  the  fire 
and  is  able  to  extinguish  a  small  fire  without  any  hydrant 
connection  at  all.  It  is  really  a  large  carbon  dioxide  fire 
extinguisher  in  which  a  solution  of  sodium  bicarbonate 
and  concentrated  sulphuric  acid  is  used.  In  addition 
small  hand  extinguishers  are  carried  by  the  chemical 
engine.  The  "  steamer  "  is  a  true  engine  in  which  steam 
is  generated  over  a  soft  coal  fire.  The  steam  in  the  engine 
drives  a  powerful  double  acting  force  pump.  This  force 
pump  draws  water  from  any  source  hydrants,  reservoirs, 
wells,  or  rivers,  and  will  throw  a  stream  of  water  more 


262     HOW  THE   COMMUNITY  SAFEGUARDS  LIFE 


than   one  hundred  feet.     The    action  of   the  pump  will 
readily  be  seen  by  studying  the  figure  which  shows  how 

the  piston  rod  of  the 
steam  engine  is  joined 
to  the  piston  of  the 
pump. 


CONNECTED 0/ffECTLY 
TOP/STONOrSTEAM 
ENGINE 


Explain  how  the  piston  in  moving  back  and  forth 
drives  water  out  on  each  stroke. 


Experiment.  —  To  see  how 
the  force  pump  works. 

Materials:  Glass  model 
force  pump  with  air 
chamber.  Shallow  jar 
or  basin. 

Method:  Operate  the 
pump.  Watch  the 
valves. 

Results  and  Conclusion: 
Explain  the  action. 
What  seems  to  be  the 
purpose  of  the  air 
chamber? 

Application:  What  ad- 
vantage over  this  type 
would  the  double  act- 
ing force  pump  used 
on  fire  engines  have  ? 


Other  fire  equip- 
ment. —  In  addition  to  the  engines,  firemen  must  have 
means  of  reaching  the  fire  from  the  outside,  and  also 
means  for  cutting  through  roofs  and  pulling  or  push- 
ing over  partly  burned  walls.  The  hook  and  ladder 
answers  this  purpose.  In  some  large  cities  water  towers 
are  used  which  are  really  extension  ladders,  bearing 
a  large  nozzle  from  which  a  stream  of  water  may  be 
directed  to  better  advantage ;  safety  nets  to  catch 
people  who  may  have  to  jump  from  windows  in  burning 


THE  FIRE  ALARM   SYSTEM 


263 


buildings  are  also  a  part  of  the  equipment.  We  also  find 
most  up-to-date  fire  departments  equipped  with  oxygen 
helmets  by  means  of  which  firemen  may  go  into  dense 
smoke  without  being  suffocated.  They  also  have  pul- 
motors  by  means  of  which  persons  who  have  been  suffo- 


Ladder  truck  with  hooks,  poles,  axes,  and  chemical  equipment. 

cated  may  be  brought  to  normal  breathing.  The  pul- 
motor  gives  oxygen  under  pressure  to  the  lungs  of  a 
suffocated  person  at  regular  intervals,  in  somewhat  the 
same  way  as  air  is  given  by  the  Shaefer  method  of  re- 
suscitation. 

The  fire  alarm  system.  —  The  first  fire  alarm  telegraph 
system  was  installed  in  Boston  in  1852.  The  original 
box  contained  practically  nothing  but  a  telegraph  key 
operated  by  a  notched  wheel  that  opened  and  closed  the 
circuit.  To-day  there  is  scarcely  a  city  or  large  town 
which  does  not  have  a  telegraphic  system.  The  red  fire 
alarm  box  that  you  find  along  your"  city  streets  contains 
clock  work  which  is  started  when  the  lever  is  pulled  down. 
A  "  character  wheel  "  is  made  to  revolve.  This  opens  and 
closes  an  electric  circuit  at  regular  intervals  causing  the 


264     HOW  THE  COMMUNITY  SAFEGUARDS  LIFE 


box  number  to  be  sounded  at  headquarters.  The  number 
of  the  box  is  made  by  the  arrangement  of  cogs  and  spaces 
on  the  "  character  wheel."  For  instance,  to  give  the  signal 
i — 3 — 2—  -  the  "  character  wheel  "  would  have  one  cog 

with  a  long  space  either 
side.  Then  three  cogs 
are  separated  by  short 
spaces,  but  are  followed 
by  a  long  space.  After 
which  there  are  two  cogs 
separated  by  a  short 
space.  All  this  is  fol- 
lowed by  an  extra  long 
space.  Each  cog  closes 
the  circuit,  while  between 
the  cogs  the  circuit  is 
broken ;  a  larger  break  in 

Inside  mechanism  of  first  fire  alarm  box,  used     the   drCuit    Separates  the 
in  Boston  in  1855.  first    signal    from    the    re- 

peated  signal.  In  the  modern  system  all  wires  are  placed 
underground.  This  improves  the  efficiency  of  the  system 
and  also  the  appearance  of  the  streets. 

Fire  traffic  regulations.  —  In  late  years  motor  fire  ap- 
paratus has  rapidly  replaced  horse-drawn  apparatus.  Its 
greater  speed  has  reduced  fire  losses,  but  at  the  same  time 
has  increased  the  danger  to  traffic.  Accidents  from  col- 
lision between  fire  apparatus  and  other  vehicles  are  usually 
due  to  carelessness  of  general  traffic.  Many  of  these 
accidents  could  have  been  avoided  by  more  efficient  laws, 
and  by  better  means  of  warning  of  the  approach  of 
fire  apparatus.  In  some  places  semaphores  and  warning 
gongs  are  placed  at  corners  where  much  traffic  passes,  and 


FIRE  PROTECTION  IN  PUBLIC  BUILDINGS      265 


city  ordinances  are  made  which  prevent  vehicles  from 
standing  near  fire  hydrants,  or  stopping  in  certain  streets 
close  to  where  fire  houses  are  located. 

Fire  protection  in  public  buildings.  —  It  was  reported 
by  the  Russell  Sage  Foundation  that  fire  wipes  out  of  exist- 
ence each  week  of  the  year  in  the  United  States,  ten  school 
buildings,  two  college  buildings,  two  hospitals,  three  public 
halls,  two  jails,  and 
twenty-six  hotels.  In 
1918  the  damage  to 
school  buildings  alone 
was  over  $5,500,000. 
Buildings  can  be  re- 
placed but  lives  can- 
not. Thousands  lose 
their  lives  in  fires 
every  year,  and  as  a 
rule  public  buildings, 
especially  schools,  are 
not  properly  pro- 
tected against  fire. 
Every  school,  orphan- 
age, hospital,  and 

other  public  building  ought  to  be  equipped  with  a  private 
fire  alarm  system,  and  in  schools  this  system  should  be 
arranged  so  that  it  can  be  detached  from  the  city  alarm 
when  fire  drills  are  held.  Most  fires  that  occur  in  schools 
originate  in  closets  or  in  the  basement;  therefore,  these 
parts  of  the  building  should  be  equipped  with  an  auto- 
matic sprinkler  system.  By  means  of  such  a  system 
whenever  a  certain  temperature  is  reached  in  a  room, 
the  valves  which  close  the  water  pipes  automatically  open 


These  sprinkler  heads  opened  very  soon  after  a 
small  fire  was  started  on  the  floor  and  the  fire 
was  quickly  extinguished. 


266     HOW  THE   COMMUNITY  SAFEGUARDS  LIFE 


The  soft  solder  which  holds  the  valve  closed  melts  at  about  180°  F.  When  melted  it 
opens  in  the  fraction  of  a  second.  The  pictures  above  were  taken  with  a  moving  pic- 
ture camera. 

through  the  melting  of  a  soft  metal  cap,  and  the  water  flows 
out  to  extinguish  the  fire. 

Experiment.  —  To  demonstrate  the  auto- 
matic sprinkler. 

Materials:  A  sprinkler  demonstration 
set.  (This  outfit  can  be  obtained  at 
cost  from  the  General  Fire  Extin- 
guisher Co.,  Providence,  R.  I.) 

Method:  Place  the  sprinkler  demon- 
strating set  over  a  sink  or  place  a 
large  heavy  paper  under  it  to  protect 
the  table  top.  A  large  shallow  pan 
will  catch  most  of  the  water.  A  small 
metal  dish  (D)  to  hold  the  fire  is 
placed  in  the  larger  pan  and  is  sepa- 
rated from  it  by  a  thick  layer  of 
asbestos.  Shredded  asbestos  wet 
with  denatured  alcohol  is  placed  in 
the  small  dish,  covering  the  base  to  a 
depth  of  I  inch.  "  Canned  heat  " 
may  be  used  in  its  place.  A  glass 
cylinder  is  used  to  prevent  the  water 
from  spreading  too  much.  This  is 
supported  by  the  iron  ring  (A)  a 
few  inches  above  the  fire  pan.  Ad- 
just the  elbow  (C)  to  5  inches  above 
the  iron  ring.  The  pipe  (B~)  is  filled 
Sprinkler  demonstrating  set.  with  water  and  the  fire  lighted. 


SAFETY  OF  LIFE  AND  PROPERTY 


267 


Result  and  Application:   Describe  just  what  happens  and  apply  the  re- 
sult to  a  real  fire  in  a  school  basement. 

Fire  regulations.  —  In  nearly  every  large  community 
the  city  government  has  passed  certain  ordinances  re- 
lating to  fire  hazards.  These  regulations  relate  to  the 
storage  of  inflammable  materials,  to  the  location  of  ga- 
rages, to  the  methods  used  in  building,  to  the  location  of 
exits  and  fire  escapes  on  buildings,  to  the  use  of  fire  safe- 
guards in  theaters,  and  to  the  separation  of  the  more  con- 
gested districts  into  fire  zones  where  stricter  regulations 
against  fire  are  enforced.  Every  citizen  of  any  com- 
munity should  make  it  his  business  to  see  that  the  fire 
laws  in  the  town  are  obeyed.  Do  you  know  what  the 
regulations  in  your  com- 
munity are?  If  not,  a 
project  in  the  form  of  a 
report  to  the  class  would 
be  very  helpful. 

Other  departments 
concerning  the  safety  of 
life  and  property.  - 
There  is  scarcely  a  city 
department  which  does 
not  in  some  way  con- 
tribute to  the  safety  of 

the  Citizens    and   Of  their  The  sealer  of  weights  and  measures  prevents 

_,„            ,              T>       -j  AI  much   fraud.     Explain    how  the    dishonest 

property.        Besides  the  dealer  who   used   the  scales  shown  above 

r                  ,.  cheated  his  customers. 

fire,    police,    and   health 

departments  we  have  the  department  of  streets,  which 
looks  after  construction,  pipe  laying,  and  keeping  the 
streets  and  sidewalks  safe  for  public  use;  the  water 
department,  which  furnishes  water  to  extinguish  fires  as 


268     HOW  THE   COMMUNITY  SAFEGUARDS  LIFE 

well  as  for  home  or  factory  use;  the  building  inspectors, 
who  prevent  new  fire  hazards ;  the  department  of  weights 
and  measures,  which  prevents  fraud  through  the  use  of 
false  weights  and  measures;  the  department  of  street 


A  hazardous  practice.    How  much  better  it  would  be  always  to  avoid  danger.     (Trav- 
elers Insurance  Co.) 

lighting,  which,  as  we  have  seen,  helps  to  make  the  city 
safe  at  night,  and,  finally,  each  individual  in  the  com- 
munity who  must  play  his  part. 

How  citizens   may  help.  — "  Safety  first  "   is   a  very 
good  slogan ;  not  only  one's  own  safety  but  that  of  the 


THE  SCORE  CARD 


269 


other  fellow,  and 
safety  of  the  prop- 
erty of  others ;  care 
on  your  part  of 
city  supplies ;  help 
on  your  part  that 
city  ordinances  are 
enforced ;  willing- 
ness on  your  part 
to  cooperate  in 

obeying  all    laWS   Or      Washing  windows  without  a  safety  strap  is  dangerous. 

ordinances  with  ref- 
erence to  safety  of  buildings ;    and,  finally,  willingness  to 
enter  into  such  routine  as  the  fire  drill  in  school,  for  by 
means  of  this  same  fire  drill  a  score  of  lives  may  be  saved  if 
a  real  school  fire  occurs. 

The  score  card.  —  A  study  of  the  two  previous  chap- 
ters, together  with  such  visits  as  you  may  make  to  a  fire 
house  and  a  police  station,  ought  to  give  you  a  good  idea 
of  how  to  score  your  own  community  on  this  card.  Be 
critical  in  your  score  so  that  any  weak  points  may  be  called 
to  the  attention  of  the  proper  authorities.  If  you  have 
made  a  real  investigation,  the  score  card  may  be  of  value ; 
if  not,  it  is  worthless. 

REFERENCE  BOOKS 

Articles  on  Safety  from  Fire,  etc.    The  American  City. 

Traffic  Regulations,  Oct.,  1919.    The  American  City. 
Brown,  Health  in  Home  and  Town.    D.  C.  Heath  and  Company. 
Croker,  Fire  Prevention.    Dodd,  Mead  and  Company. 
Crump,  Boy  Scout  Fire  Fighters.    Barse  and  Hopkins. 
Crump,  Boys'  Book  of  Firemen.    Dodd,  Mead  and  Company. 
Crump,  Boys'  Book  of  Policemen.    Dodd,  Mead  and  Company. 
Finch,   Everyday  Civics.    American  Book  Company. 


270     HOW  THE   COMMUNITY  SAFEGUARDS  LIFE 

SCORE  CARD.    SAFEGUARDING  LIFE  AND  PROPERTY  IN  THE 
COMMUNITY 


PERFECT 
SCORE 

MY 
SCORE 

STREET  LIGHTING 
Lamps  lighted  cloudy  and  moonless  nights  (5) 
No  dark  areas  between  the  lights  (5) 
Wires  in  business  section  underground  (5) 
Lighting  service  well  maintained  (5) 

20 

STREET  TRAFFIC 
No  "blind"  corners  (5) 
Traffic  "cop"  at  congested  street  intersections,  and 
at  schools  on  streets  with  much  traffic  (10) 
No  grade  crossings  (5) 
Traffic  regulations  enforced,  indicated  by  few  street 
accidents  (10) 

30 

POLICE 
Report  neglect  on  part  of  careless  citizens  (5) 
Little  or  no  lawlessness  goes  unpunished  (5) 
Actively  aid  other  departments  (5) 
Efficient  in  detective  work  (5) 

20 

FIRE  DEPARTMENT 
Paid  firemen  on  day  duty  (25),  night  duty  (23) 
Hydrants,  reservoirs,  or  natural  bodies  of  water 
within  300  feet  of  any  buildings  (5) 
A  motor  chemical  engine  (5) 
A  "steamer"  and  a  "hook  and  ladder"  truck  (5) 
An  electric  fire  alarm  signal  system  (5) 
Strict  fire  laws  and  building  regulations  in  business 
area  enforced  (5) 

30 

TOTAL 

IOO 

REFERENCE  BOOKS     (Continued) 

Garber,  Course  of  Study  in  Civics,  Grades  7  and  8. 

Hughes,  Community  Civics.     Allyn  and  Bacon. 

Jeness,  Bucket  Brigade  to  Flying  Squadron.     G.  H.  Ellis  Company. 

Kenlon,  Fires  and  Firefighters.     G.  H.  Doran  Company. 

Moffett,  Careers  of  Dagger  ani  Daring.    The  Century  Company. 

The  Fire  Department.  Leaflet  36,  Municipal  Civics.    Board  of  Education,  Newark. 

The  Trial  of  Fire,  March,    1921 ;  Five  Years  of  Fire  Waste,  May,  1921.     General 

Science  Quarterly.  -    *  v 

Weeks,  The  Avoidance  of  Fires.}   .For  teachers.)    D.  C.  Heath  and  Company. 
Whitman.  Fire  Hazards  and  Safeguards-    TO  Lessons.     Genera)  Science  Quarterly. 

March,  iy>o 
Ziegler  and  Jaquette,  Our  Community.    J.  C.  Winston  Company- 


CHAPTER  XVIII. 
ADVANTAGES  FOR  EDUCATION  AND  RECREATION 

Problems.  —  i.  To  learn  about  the  development  and  work 
of  schools. 

2.  To  see  what  building  construction  and  equipment  is 
required  for  the  welfare  of  children  in  schools. 

3.  To  see  how  libraries   and  museums   may  aid  in  our 
education. 

4.  To  see  the  value  of  public  playgrounds  and  parks. 

5.  To  see  how  various  amusements  may  also  be  educa- 
tional. 

6.  To  see  what  community  forces  are  working  for  higher 
standards  of  morality  and  to  aid  moral  education. 

Project  I.  —  To  LEARN   THE    EDUCATIONAL  POSSIBILITIES  OPEN 

TO  BOYS  AND  GIRLS  IN  MY  LOCALITY. 

Project  II.  —  To  MAKE  A  STUDY  or  THE  WAYS  IN  WHICH  LIBRARIES, 

MUSEUMS,  AND  PARKS  CAN  ASSIST  IN  MY  EDUCATION. 

What  city  taxes  pay  for.  —  A  city  budget  is  made  out  not 
only  to  insure  us  pure  water  and  milk,  to  pave  our  streets, 
to  give  us  a  fire  department  to  protect  us  from  fire,  and 
police  to  guard  us  while  we  sleep,  to  give  us  scavengers  to 
carry  off  our  refuse,  and  street  cleaners  to  keep  the  streets 
clean,  but  it  also  must  provide  for  the  moral,  the  educa- 
tional, and  the  physical  well  being  of  the  citizens.  Taxes 
must  provide  for  our  schools,  our  public  libraries,  our  play- 
grounds, and  our  parks. 

271 


272 


ADVANTAGES  FOR  EDUCATION 


The  development  of  the  public  schools  in  this  country.  - 
Among  the  first  laws  that  the  Massachusetts  Colony  passed 
was  one  which  provided  that  in  each  settlement  of  fifty 
householders,  intermediate  schools  must  be  established, 

and  in  every  town  of 
one  hundred  house- 
holders a  grammar 
school.  This  was 
the  foundation  of 
our  free  school  sys- 
tem which  now  is 
established  in  every 
state  and  territorial 
possession.  Con- 
gress in  1 787  passed 
an  ordinance  for 
the  government  of 

new  lands  in  the  West  which  provided  that,  "  religion, 
morality,  and  knowledge  being  necessary  to  good  govern- 
ment and  the  happiness  of  mankind,  schools  and  the 
means  of  education  shall  forever  be  encouraged. " 
;  As  the  schools  grew  in  the  East,  private  schools  came  into 
existence  largely  for  the  purpose  of  those  who  wished  to 
go  to  college.  Some  of  these  academies  still  exist  in  the 
well-known  schools  at  Andover  and  Exeter,  and  others 
scattered  throughout  the  East.  Since  this  country  is  a 
democracy,  and  schools  and  education  are  the  right  of  all 
people,  the  public  school  system  gradually  is  crowding 
out  the  private  schools,  especially  throughout  the  West. 
Here  a  complete  state  system  of  education  is  worked  out, 
for  here  we  find  elementary  and  secondary  schools  leading 
directly  to  the  state-controlled  colleges  and  universities. 


The  first  free  public  school    in    America   was  estab- 
lished in  Dedham,  Massachusetts,  in  1644. 


LAWS  REGARDING  ATTENDANCE  273 

Different  states  have  different  methods  of  control  of  public 
instruction,  although  in  general  there  is  a  state  superin- 
tendent of  public  instruction  or  commissioner  of  educa- 
tion either  elected  by  the  people  directly  or  appointed  by 
the  government.  The  state  board  of  education,  or  the 
state  commissioner  of  education,  plans  and  maintains  uni- 
form standards  in  the  schools.  State  money  is  also  appro- 
priated for  public  school  purposes.  Teachers  are  usually 
supplied  from  normal  schools  which  are  also  under  state 
control.  These  normal  schools  usually  have  training 
schools  where  the  young  teachers  may  work  under  super- 
vision with  the  pupils  whom  they  are  to  teach  later.  The 
Commissioner  of  Education  at  Washington  assists  in 
the  educational  work  of  the  whole  country  and  through 
educational  publications  supplies  information  and  makes 
public  such  new  experiments  in  education  as  are  worth 
while. 

Laws  regarding  attendance  at  school.  —  In  most  states 
children  are  required  to  attend  school  from  eight  to  ten 
years.  The  average  age  is  from  seven  to  fifteen.  It  is 
possible  for  children  in  many  communities  to  go  through 
the  entire  system  from  kindergarten  to  college  without  any 
cost,  even  free  textbooks  being  provided  in  many  cities. 
Statistics  show  that  those  who  go  to  high  school  get  much 
better  living  wages  than  those  who  stop  their  education 
before  high  school  age,  and  those  who  go  to  college  receive 
even  more  salary  and  a  higher  place  in  the  world.  Of  the 
men  and  women  whose  names  are  in  "Who's  Who"  a  very 
large  percentage  are  college  graduates.  But  since  only  a 
small  percentage  go  through  college  our  schools  are  con- 
tinually placing  new  "  practical  "  subjects  in  the  curricu- 
lum so  that  a  girl  or  boy  may  be  more  useful  at  home  or 

H.   W.   CIV.   SCI.   COMM. l8 


274 


ADVANTAGES   FOR  EDUCATION 


in  the  business  of  life  into  a  which  he  may  be  called.  Sew- 
ing, cooking,  woodworking,  metal  working,  and  commercial 
branches  of  various  kinds  have  all  been  introduced  into 
the  schools.  Mental  tests  are  now  being  used  in  many 
school  systems  so  that  those  who  have  little  ability  for 

book  work  may  be 
helped  to  a  more 
useful  kind  of  educa- 
tion in  the  voca- 
tional schools  which 
train  for  practical 
everyday  work. 

The    school   sys- 
tem of  a  great  city. 
-  The  city  of  New 

A  high  school  in  New  York.  1      .  ,     ,  , 

York  has  probably 

the  largest  school  system  in  the  world,  including  more 
than  five  hundred  elementary  schools,  thirty  secondary 


Foreign  born  learn  to  be  Americans  in  night  school. 

schools,  several  teachers'  training  schools,  and  two  col- 
leges. These,  together  with  its  twenty  thousand  teach- 
ers, give  enormous  opportunities  for  free  education  for 
those  who  wish  to  go  to  the  top  of  the  ladder.  All  books 


SCHOOLS    AND    THEIR    WORK  275 

and  many  other  materials  are  free.  Night  schools  and  free 
lectures  are  provided  to  help  those  who  cannot  give  day 
time  to  school  work.  Vocational  schools  and  continuation 
schools  are  an  additional  part  of  the  system  of  education ; 
while  summer  schools  and  public  playgrounds  offer  work 
and  play  for  many  more. 

In  New  York  about  twenty  per  cent  of  the  total 
budget  goes  to  defray  the  expenses  of  running  the  public 
schools,  —  much  more  than  for  any  other  city  department. 
About  five  per  cent  of  the  people's  money  is  spent  for 
charitable  purposes,  about  two  per  cent  for  parks,  play- 
grounds, and  museums,  and  about  one  per  cent  for  correc- 
tional purposes.  Schools  in  many  cases  are  used  for 
recreation  centers  at  night;  over  fifty  of  these  centers 
have  an  average  attendance  of  twenty-five  thousand  a 
night.  For  all  this  the  city  expends  the  very  large  sum  of 
over  forty  million  dollars  a  year. 

Schools  and  their  work.  —  Most  of  us  take  the  public 
schools  as  a  matter  of  course,  and  do  not  always  even  say 
"  thank  you."  As  a  matter  of  fact,  the  public  school 
system  in  this  country  is  something  for  all  of  us  to  be 
proud  of.  Nearly  $500,000,000  a  year  is  spent  for  free 
schools,  an  average  of  $26  per  child  enrolled.  This  de- 
mocracy of  ours  will  be  great  because  the  children  avail 
themselves  of  educational  advantages.  A  child  may  get 
much  from  our  free  system  of  education,  but  later  we  ex- 
pect him  to  pay  for  it,  and  more,  in  his  work  as  a  citizen. 
Schools  should  train  for  life  in  the  community  because  the 
school  is  a  kind  of  community.  It  should  train  for  citizen- 
ship by  making  every  subject  we  study  help  us,  in  some 
way,  to  become  better  citizens.  Science  should  teach  us  to 
think  straight  and  to  understand  many  civic  problems ; 


276 


ADVANTAGES  FOR  EDUCATION 


language  will  help  us  to  speak  and  write  intelligibly ;  history 
and  civics  will  show  us  how  to  become  good  citizens. 
Athletics  ought  to  help  us  toward  certain  splendid  stand- 


Ideal  plan  for  rural  school  grounds.     Can  you  plan  better  grounds  for  your 
community  ? 

ards  of  citizenship:  honesty,  good  sportsmanship,  quick- 
ness in  decision,  and  square  dealing  with  the  other  fellow. 
Colleges,  universities,  and  technical  schools.  —  All 
parts  of  our  land  to-day  are  supplied  with  institutions  of 
higher  learning.  More  and  more  the  young  people  of  this 
country  are  availing  themselves  of  the  opportunities  for 
higher  education.  Especially  is  this  true  in  science.  We 


MODERN  SCHOOL  BUILDINGS 


277 


have  awakened  to  the  fact  that  training  in  science  is  neces- 
sary not  only  for  straight  thinking  but  also  for  advance- 
ment in  the  world  of  to-day.  Engineering  schools,  medi- 
cal schools,  and  all  kinds  of  technical  schools  are  to-day 
more  important  than  ever  before,  and  their  attendance 
is  growing  year  by  year.  Manufacturing  and  engineering 
corporations  are  endowing  scholarships  so  that  worthy 
young  men  in  their  employ  may  get  a  free  education  along 
lines  necessary  to  earn  promotion.  No  young  man  with 
ability  to-day  need  fear  that  he  may  not  succeed  if  he  is 
willing  to  work. 
Modern  school  buildings.  —  The  modern  school  build- 


Ad  justable  seats  and  desks. 

ing  should  be  fireproof  since  many  children  are  within  it 
for  several  hours  each  school  day.  It  should  have  wide, 
well-lighted  halls  and  stairs  and  attached  fire  escapes  to 
give  quick  exit  in  case  of  fire.  The  school  should  be 
equipped  with  fire  alarm  signals  connected  directly  with 
the  city  system,  and  all  fire  hazards  should  be  eliminated. 
The  large,  airy  rooms  should  have,  where  possible,  outside 
overhead  lighting,  and  where  this  is  not  possible,  light 
should  come  in  from  large  windows  on  one  side  of  the  room 
only,  so  that  no  shadows  are  formed  on  the  paper  when 


278 


ADVANTAGES  FOR  EDUCATION 


Curtains   adjustable  at  both  top   and   bottom 
remove  much  glare  and  eye-strain. 


children  are  writing.  The  desks  and  seats  should  be  adjust- 
able, so  that  each  individual  child  may  have  a  desk  of  the 
right  height.  The  arti- 
ficial lighting  should  be 
arranged  to  give  plenty 
of  light  without  glare. 

The  ventilation  system 
should  be  so  arranged 
that  the  air  is  passed 
through  a  strainer,  by 
which  dust  and  germs 
are  in  part  removed, 
and  the  warm  air  sflould 
be  passed  over  a  hu- 
midifier so  as  to  have 
the  proper  amount  of 
moisture.  For  this  purpose  in  many  schools  steam  is 
passed  into  the  air  ducts.  In  schools  where  the  air  is  dry, 

pans  of  water  should  be  kept  on 
the  radiator. 

Since  hygiene  is  taught  in  the 
schools,  it  should  be  practiced  in 
every  way.  Sanitary  drinking 
fountains  should  always  be  pro- 
vided. The  bubble  fountain  with 
the  nozzle  stream  pointing  directly 
upwards  has  been  proved  in- 
sanitary. The  best  form  is  one 
which  throws  a  stream  out 
to  one  side,  so  that  the  lips  may 
not  be  pressed  against  any  part  of  the  fountain.  It 
goes  without  saying  that  individual  paper  towels  should  be 


A  good  fountain  for  public  use. 


LIBRARIES  AS  A  PUBLIC  ASSET 


279 


placed  in  the  wash  rooms  and'  that  the  toilet  and  urinals 
should  have  no  wood  in  their  construction,  should  be 
well  ventilated,  and  flushed  frequently. 

Dry  sweeping  should  not  be  allowed.  Experiments 
in  certain  New  York  schools  have  shown  that  where  dry 
sweeping  is  done  by  careless  janitors'  assistants  the  bac- 
terial content  of  the  air  in 
the  rooms  becomes  very 
great,  owing  to  the  constant 
movement  of  the  children 
in  the  rooms  and  halls.  Any 
school  that  lives  up  to  the 


standards  just  given  will  be    Plate 

a  credit  to  its  community. 

Do  your  own  schools  measure  up  to  the  standard  ? 

Libraries  as  a  public  asset.  —  What  would  the  average 
school  boy  or  girl  do  without  the  public  library?  We 
have  come  to  regard  it  as  a  part  of  our  environment, 


A  library  reading  room. 


thanks  to  the  benefactions  of  Andrew  Carnegie  or  some 
wealthy  citizens  of  our  own  town.  Not  only  do  most 
communities  have  free  libraries,  but  many  of  them  use  the 
building  for  more  than  the  purpose  of  taking  out  books. 


280  ADVANTAGES  FOR  EDUCATION 

Many  boys  and  girls  not  fortunate  enough  to  have  a  quiet 
room  of  their  own  in  which  to  study  use  the  reading  room 
of  the  public  library  or  some  room  that  is  set  apart  for  the 
purpose  of  study.  Libraries  are  used  as  meeting  places  for 
literary  and  other  clubs,  and  for  lectures  as  well.  Mod- 
ern libraries  have  specially  fitted  children's  rooms  with 
the  most  interesting  children's  books ;  they  use  attractive 
bulletin  boards  on  which  to  display  the  latest  topics  of 
interest,  and  many  a  boy  and  girl  has  here  formed  the 
habit  of  reading  good  books.  This  habit  will  prove  of 
much  value  in  later  life.  The  newspapers  and  periodicals 
in  the  library  are  also  helpful  in  our  education. 

How  public  libraries  are  maintained.  —  Many  libraries 
are  endowed  and  receive  the  income  from  such  endow- 
ment for  their  running  expenses,  but  on  the  other  hand,  most 
of  the  libraries  are  supported  wholly  or  in  part  from  public 


Minerals  and  gems  displayed  in  American  Museum  of  Natural  History. 

funds  raised  by  taxation.  The  Carnegie  libraries  were 
given  to  communities  only  on  condition  that  the  cost  of 
their  upkeep  would  be  met  by  the  citizens  of  the  com- 
munity. Some  states  control  not  only  the  large  li- 
brary at  the  capital  but  also  traveling  libraries  which 


PLAYGROUNDS  AND  PLAYGROUND  MOVEMENT      281 


Class  taking  notes  at  the  Aquarium  in   New 
York. 


are  sent  from  one  small  place  to  another,  each  one  re- 
maining in  a  given  place  for  a  few  weeks  and  then  moving 
on.  In  this  way  small  communities  are  constantly 
supplied  with  new  books 
at  a  relatively  low  cost. 

Art  and  other  mu- 
seums as  educational 
aids.  —  Indirectly  a  great 
museum  is  one  of  the 
finest  means  of  getting 
an  education.  Most  of 
our  large  cities  have  col- 
lections of  paintings 
and  sculpture.  There  are  also  museums  of  natural 
history  as  well  as  commercial  or  economic  museums. 
Examples  of  such  are  the  American  Museum  of  Natural 
History  in  New  York,  the  Commercial  Museum  in  Phila- 
delphia, the  Fine  Arts  Museum  of  Boston,  the  Carnegie 
Museum  in  Pittsburgh,  and  the  Field  Museum  of  Chicago. 
In  most  cases,  either  the  building,  the  contents,  or  both 
are  gifts  of  public-spirited  citizens,  and  the  community's 
only  duty,  if  any,  is  to  maintain  the  upkeep.  Most  mu- 
seums have  lecture  courses,  loan  collections  to  public 
schools,  have  rooms  set  apart  to  which  the  collections 
may  be  taken  by  students  and  teachers  and  in  which 
laboratory  work  may  be  done.  In  these  and  many  other 
ways  a  most  important  part  in  rounding  out  the  education 
of  boys  and  girls  is  accomplis-hed.  It  is  estimated  that  a 
total  of  over  2,500,000  persons  visit  the  three  great 
museums  of  New  York  and  Brooklyn  annually. 

Playgrounds    and    the    playground    movement.  —  Any 
boy  who  reads  this  chapter  may  well  object  that  up  to  the 


282  ADVANTAGES  FOR  EDUCATION 

present  time  nothing  has  been  said  about  recreation.  He 
might  well  ask,  "  What  does  the  city  do  for  a  red-blooded 
boy?  "  Fortunately,  we  have  come  to  realize  that  boys 
and  girls  of  school  age  need  play  and  recreation  as  well  as 
work.  In  the  past  ten  years  hundreds  of  playgrounds 
have  been  opened  in  cities  or  towns,  maintained  by  the 
park  departments,  boards  of  education,  settlement  houses, 
or  associations  interested  in  the  playground  movement. 
In  these  places  boys  and  girls  as  well  as  grown-ups  can 


The  place  for  enjoyable  exercise  in  summer. 

play  in  safety  and  under  the  supervision  of  a  trained  play- 
ground instructor.  In  many  large  cities  we  find  one  play- 
ground to  each  ten  thousand  inhabitants,  especially  in 
congested  communities,  where  the  playground  movement 
is  a  great  boon.  In  some  cities  it  is  the  custom  to  keep 
traffic  off  some  streets  during  certain  hours  in  the  after- 
noon so  that  children  may  play  in  safety  near  their  homes. 
Massachusetts  in  1908  passed  a  wise  law  providing  that 
cities  of  over  10,000  should  provide  and  maintain  a  public 


TYPES  OF  PLAYGROUNDS 


283 


playground.  As  we  have  seen,  many  cities  now  have  their 
own  forester  and  are  caring  for  their  shade  trees  and  plant- 
ing new  ones.  It  is  the  wise  city  that  looks  into  the  future. 
Is  your  community  one  of  these? 

Some  types  of  playgrounds.  —  Many  cities,  notably 
New  York,  Chicago,  and  Washington,  have  well-equipped 
playgrounds  and  recreation  centers  with  club  houses,  swim- 
ming pools,  bath 
houses,  out-  and  in- 
door gymnasiums, 
running  tracks,  and 
fields  for  games. 
School  yards,  and 
the  roofs  of  school 
buildings  are  set 
apart  for  playgrounds 
in  some  localities. 
These  are  especially 
useful  for  basket  ball 
and  games  requiring 
a  small  space.  In 
communities  which 
border  on  bodies  of 
water,  recreation 
piers  are  built  which 
are  furnished  with  comfortable  seats,  with  sand  boxes 
and  other  amusements  for  young  children.  Here  in  the 
evening  bands  play  and  free  dancing  is  enjoyed.  Many 
schoolhouses  are  now  thrown  open  evenings  for  com- 
munity dancing.  Public  baths,  swimming,  and  bathing 
are  found  in  most  cities,  especially  those  near  bodies  of 
water.  New  York,  for  example,  has  twenty-one  bath 


The' public  bath  is  popular  with  the  boys. 


284 


.ADVANTAGES   FOR  EDUCATION 


houses  scattered  throughout  the  city,  thirteen  free  floats,  and 
a  very  large  municipal  bath  house  at  Coney  Island,  fur- 
nished with  accommodations  for  nearly  7000  persons  at  one 
time.  Over  12,000,000  separate  baths  have  been  given 
in  a  single  year  by  these  agencies  in  the  city  of  New  York. 
Public  parks  and  their  use.  —  Public  parks  have  been 
rightly  called  the  "  breathing  places  of  a  city."  We  all 
know  the  value  of  green  plants  in  giving  off  oxygen  to  the 


Parks  are  the  "  breathing  places  "  of  our  large  cities. 

air,  and  absorbing  carbon  dioxide  from  it.  Many  cities 
are  provided  with  park  systems  embracing  thousands  of 
acres.  Chicago,  for  example,  has  seven  large  and  five  small 
parks,  and  about  forty  miles  of  parkway  connecting  these. 
The  city  of  New  York  has  a  system  comprising  237  parks 
with  a  total  of  nearly  8000  acres  of  land.  This  park 
system  includes  one  of  the  finest  and  largest  zoological 
parks  in  the  world  as  well  as  three  free  museums  of  large 


THE  MOVING  PICTURE  285 

size  and  several  historical  buildings  which  are  open  to  the 
public.  Washington,  D.  C.,  has  a  wonderful  system  of 
large  and  small  parks  which,  combined  with  the  museums 
and  botanical  gardens  and  the  experimental  stations  of 
the  zoological  park,  make  it  one  of  the  most  useful  ad- 
juncts available  to  public  education. 

Not  very  long  ago  parks  were  looked  upon  as  show 
places.  Now,  however,  they  are  more  than  that  for  they 
have  become  a  part  of  the  great  public  playgrounds.  Golf 
links  and  public  tennis  courts  are  found  in  most  of  these 
parks.  We  have  baseball  and  polo  in  summer  and  hockey 
and  skating  in  winter.  Every  opportunity  is  given  to  the 
citizens  for  healthful  exercise.  This,  added  to  the  beauty 
of  the  parks,  makes  a  citizen  feel  that  the  money  put  into 
public  parks  is  well  spent. 

Other  means  of  education  and  recreation.  —  Perhaps 
the  finest  example  of  community  spirit  is  seen  in  the  for- 
mation of  community  centers.  More  and  more  these 
organizations  combine  the  club  and  social  forum  with  the 
playground  and  education.  Here  is  a  place  where  lectures 
and  concerts  may  be  given,  a  place  where  community  dances 
may  be  held  under  proper  supervision,  and  where  pageants 
or  social  gatherings  may  be  held. 

The  moving  picture  as  an  educational  factor.  —  The 
moving  picture  has  come  to  stay  and  may  be  used  as  an 
educational  asset  if  one  chooses  wisely  which  films  he  shall 
see.  During  the  World  War  hundreds  of  thousands  of 
young  men  saw  educational  "  movies  "  in  the  huts  of  the 
Y.  M.  C.  A.  Many  of  these  " movies"  having  distinct  edu- 
cational value  illustrating  life  in  France,  England,  or  Italy 
were  shown  to  the  men  who  were  soon  to  go  to  those  coun- 
tries. At  the  present  time  the  Public  Health  Service,  as 


286  ADVANTAGES  FOR  EDUCATION 

well_as  many  manufacturing  companies,  have  collections 
of  free  films  on  different  educational  topics.  Especially 
important  are  those  of  the  Public  Health  Service 
which  show  different  aspects  of  health  and  disease. 
Is  your  community  availing  itself  of  this  opportunity  of 
seeing  these  films? 

How  moving  pictures  were  invented.  —  The  idea  of 
taking  moving  pictures  is  usually  credited  to  Edward 
Maybridge,  an  Englishman  who,  when  living  in  Cali- 
fornia in  1872,  experimented  in  taking  a  series  of  pictures 
of  moving  objects.  The  application  of  this  idea  was 
worked  out  in  the  invention  of  Thomas  Edison  called  the 
kinetoscope.  This,  thanks  to  the  development  of  the 
sensitized  film  by  the  Eastman  Kodak  Company,  was 
made  into  a  device  by  means  of  which  a  strip  of  film  was 
passed  before  an  opening  in  a  box  into  which  a  person 
looked.  Just  under  the  peep-hole  was  a  revolving  shutter. 
A  motor  caused  the  film  to  move  past  the  shutter  rapidly 
so  that  objects  in  the  picture  appeared  to  move.  The 
kinetoscope  was  exhibited  at  the  World's  Fair  in  Chicago 
in  1893,  but  attracted  little  attention  because  its  com- 
mercial possibilities  were  not  then  thought  of.  The  first 
real  moving  pictures  were  shown  in  England  in  1895  by 
Robert  Paul.  Lumiere  &  Sons  a  little  later  invented  the 
cinematograph,  which  was  first  exhibited  in  this  country 
in  1896.  Since  that  time  rapid  strides  have  been  made  in 
the  moving  picture  business.  Now,  thousands  of  people  are 
engaged  in  staging  and  manufacturing  pictures,  thou- 
sands more  operate  theaters,  and  between  fourteen  and 
fifteen  million  people  go  to  the  "  movies  "  every  day  in  the 
year  in  this  country,  while  enough  film  is  shown  each  day 
to  go  almost  around  the  globe  at  the  equator. 


PROJECTION  OF  PICTURES  287 

How  pictures  are  made.  —  A  film  made  of  celluloid  is 
employed  in  a  special  camera  for  taking  pictures.  These 
films  vary  in  length  from  a  few  feet  to  five  hundred  feet. 
The  camera  takes  photographs  of  a  moving  object  at  the 
rate  of  sixteen  to  one  hundred  and  twenty  pictures  a  sec- 
ond. Negatives  are  made  and  then  contact  prints  are 
made  on  another  roll  of  film  from  the  negatives  in  the 
same  way  as  a  positive  photograph  is  made.  Thus  many 
copies  of  the  film  may  be  made  from  one  original  negative 
and  retailed  to  various  moving  picture  houses. 

Projection  of  pictures.  —  There  are  about  sixteen  moving 
pictures  to  a  foot  of  film.  To  make  the  pictures  look 


First  machine  used  to  project  moving  pictures  in  America.     Pictures  were  exhibited 
with  this  machine  by  Jenkins,  in  Richmond,  Indiana,  on  June  6,  1894. 

life-like  they  must  be  run  through  a  machine  at  the  same 
rate  as  they  were  taken.  This  is  not  always,  done  as  we 
can  tell  when  we  see  the  rapid  movements  of  some  char- 
acters on  the  screen.  Strange  as  it  may  seem,  we  do  not 
see  the  pictures  move,  for  each  picture  remains  still  on 
the  screen  before  our  eyes  for  a  fraction  of  a  second.  We 
appear  to  see  the  picture  move  because  of  a  peculiarity  of 


288 


ADVANTAGES  FOR  EDUCATION 


ff££L  BOX ^ 

VPPEA  /?£££•+ 


SPROCKET. 
LOWfiMM          \ 
M/£LD 


Essential  parts  of  the  moving  picture  machine.    (After  Hawkins.) 


RELIGIOUS   AND  MORAL  EDUCATION  289 

the  eye.  Any  image  seen  by  the  eye  remains  impressed 
on  the  retina  or  sensitive  portion  a  fraction  of  a  second 
after  the  eye  has  seen  it.  Since  these  pictures  come  to  the 
eyes  so  rapidly  there  is  always  the  image  of  the  preceding 
picture  left  on  the  retina.  Hence  the  pictures  appear 
continuous  and  seem  to  move.  Light  is  cut  off  from  the 
screen  while  each  picture  is  being  moved  into  place.  Color 
effects  are  obtained  by  passing  the  light  through  tinted 
screens  or  by  coloring  the  film. 

With  the  establishment  of  non-combustible  films  and  the 
simplification  of  the  moving  picture  machine,  schools, 
social  clubs,  and  even  homes,  are  bound  to  be  equipped 
with  moving  picture  apparatus.  They  may  be  used  to 
demonstrate  scientific  experiments  or  discoveries  that  are 
almost  impossible  to  produce  in  the  laboratory  because  of 
the  length  of  time  involved  in  preparation ;  the  develop- 
ment of  living  plants  and  animals,  for  example,  can  be 
shown  by  moving  pictures  with  the  aid  of  animated 
labels,  a  trick  device  by  means  of  which  names  or  descrip- 
tions of  the  parts  are  then  run  into  the  picture.  Much 
educational  work  can  be  made  of  such  pictures.  The 
"  movies  "  can  be  used  to  make  geography  and  history 
and  science  more  real  and  interesting.  How  much  more 
our  Shakespearean  plays  mean  to  us  after  we  have  seen 
the  characters  on  the  screen  than  when  we  have  only  read 
the  play ;  and  when  we  think  of  the  amusement  afforded 
millions  of  people  we  are  glad  that  the  "  movies  "  have  come 
to  stay.  We  should,  however,  use  our  influence  to  have 
only  the  better  class  of  pictures  shown  in  our  community. 

Religious  and  moral  education.  —  Religion  has  played  a 
prominent  part  in  the  history  of  the  world.  The  desire  to 
spread  religion  led  the  French  and  Spanish  missionaries 

H.  W.  CIV.  SCI.  COMM.  — 19 


290  ADVANTAGES  FOR  EDUCATION 

to  establish  missions  after  they  had  colonized.  The 
Puritans  came  to  Massachusetts  Bay  to  enjoy  freedom  of 
religious  worship.  Our  Constitution  says,  "  Congress  shall 
make  no  laws  respecting  the  establishment  of  religion  or 
the  free  exercise  thereof,"  so,  as  our  country  grew  it  became 
part  of  the  belief  of  its  citizens  that  church  and  state 
should  be  separate  and  that  freedom  of  worship  should  be 
enjoyed  here.  For  that  reason  perhaps,  this  country  of 
ours  has  become  the  haven  of  every  persecuted  sect  under 
the  sun,  and  religious  tolerance  is  exercised  here  as  no- 
where else  in  the  world. 

Methods  of  giving  religious  instruction.  —  There  are 
about  fifteen  million  Catholics  and  thirty  million  Protes- 
tants in  this  country  with  several  million  Jews  and  other 
religious  bodies.  It  is  evident  from  these  figures  that 
not  all  the  people  are  members  of  church  denominations, 
but  most  of  our  people  believe  in  some  sort  of  religious  or 
moral  instruction  for  children.  Such  instruction  can  be 
obtained  and  is  given  in  the  Sunday  schools,  but  many 
people  think  the  school  is  the  place  for  this  instruction. 
This  point  has  been  much  debated  among  educators. 
Leaders  of  some  types  of  public  schools,  the  so-called  "  Gary 
Schools,"  have  made  provision  for  religious  teaching  part 
of  each  day  by  priest,  minister,  or  rabbi.  Many  private 
schools  exist  in  which  religion  is  taught.  Just  how  the 
matter  of  teaching  religion  will  be  settled  is  not  easy  to 
determine  at  the  present  time. 

Moral  instruction.  —  Since  the  welfare  of  any  com- 
munity is  directly  concerned  with  the  morals  in  that  com- 
munity, no  one  can  object  to  moral  instruction  in  the 
schools.  We  should  all  believe  in  the  law  "  Do  unto  your 
neighbor  as  you  would  like  him  to  do  unto  you  "  rather 


AIDS  TO   MORAL  EDUCATION  291 

than  the  often  substituted  one,  "  Do  your  neighbor  or  he 
will  do  you."  A  community  where  the  Golden  Rule  is 
practiced  is  surely  better  off  than  one  where  tricksters 
and  shysters  make  people  suspicious  of  each  other.  A 
certain  amount  of  competition  is  good  if  honest  and  above 
board.  Honest  practices  in  politics  and  daily  life  may  go 
far  towards  teaching  young  people  to  live  straight  and  look 
down  on  dirty  practices  in  the  home,  in  business,  and  in 
politics.  Moral  teaching  does  not  only  this  but  it  also  shows 
up  selfishness  and  greed  on  the  part  of  individuals  and 
corporations.  On  the  other  hand,  it  makes  the  employee 
recognize  the  rights  of  the  employer.  It  shows  that  life, 
if  it  is  to  be  worth  while,  is  made  up  of  "  give  and  take  " 
with  honesty  and  cooperation  as  the  corner  stones.  In 
our  anxiety  to  remove  sectarian  religious  instruction  from 
our  public  schools  we  have  forgotten  moral  instruction 
and  its  great  value.  The  leaders  in  every  community 
should  get  together  and  add  to  their  system  of  instruc- 
tion such  moral  truths  as  are  generally  acceptable  to  all 
citizens. 

Aids  to  moral  education.  —  The  World  War  has  taught 
the  value  of  welfare  agencies  such  as  the  Y.  M.  C.  A.,  the 
Y.  W.  C.  A.,  the  Knights  of  Columbus,  the  Salvation 
Army,  settlement  houses,  and  other  private  societies  in 
promoting  better  moral  and  physical  conditions  among 
the  young  men  and  women  of  our  nation.  After  all,  the 
best  way  to  teach  good  morals  is  by  example.  If  the 
men  and  women  who  represent  the  welfare  organizations 
live  lives  that  shine  in  contrast  to  those  around  them, 
if  they  show  unselfishness  and  courage,  sympathy  or  co- 
operation in  helping  others,  then  the  problem  of  better 
morals  in  the  community  is  partly  solved.  How  much 


2Q2  ADVANTAGES   FOR  EDUCATION 

better  is  the  pleasant  sociability  of  the  club  house  of  this 
sort  than  the  dance  hall  or  the  pool  room.  Prohibition  has 
placed  new  responsibilities  on  these  welfare  agencies.  They 
must  work  out  a  substitute  for  the  saloon  and  give  the 
community  a  poor  man's  club  house.  Have  the  welfare 
agencies  in  your  town  awakened  to  their  responsibility  ? 

The  score  card.  —  This  score  card  ought  to  be  made 
the  basis  of  a  class  discussion  after  different  members  of 
the  class  have  visited  and  scored  the  parts  of  their  own 
community  in  which  they  live.  By  taking  these  individual 
opinions  from  parts  of  the  community,  we  can,  after  weigh- 
ing all  the  evidence,  make  a  card  which  will  be  a  fair  esti- 
mate of  the  entire  community.  After  the  scoring  is  done, 
let  each  one  of  you  think  over  the  particular  advantages 
the  community  offers  which  you  most  need.  Are  you 
making  the  best  use  of  your  time  as  regards  these  oppor- 
tunities? 

REFERENCE  BOOKS 

Addams,  J.,  Spirit  of  Youth  and  the  City  Streets.     (For  teachers.)    The  MacmiUan 

Company. 

Articles  on  Civic  Advantages.    The  American  City,  New  York. 
Finch,  Everyday  Civics,  American  Book  Compamy. 

Forbush,  Young  Folks'  Book  of  Ideals.    Lothrop,  Lee  and  Shepard  Company. 
Handbook  of  the  Camp  Fire  Girls. 
Handbook  Boy  Scouts  of  America. 

Hodgdon,  Elementary  General  Science.    Hinds,  Hayden  and  Eldredge. 
Howe,  Modern  City  and  Its  Problems.     (For  teachers.)     Charles  Scribner's  Sons. 
Hughes,  Community  Civics.    Allyn  and  Bacon. 

Kennedy,  Newark  Study.    (For  teachers.)    Board  of  Education,  Newark,  N.  J. 
McCarthy,  et  al,  Elementary  Civics.    Thompson,  Brown  and  Company. 
Moore,  Youth  of  the  Nation.    The  Macmillan  Company. 
Municipal  Year-Book.    City  of  New  York. 
Sparks,  Business  of  Government.    Rand,  McNally  Company. 
Talbot,  Moving  Pictures.    Heinemann. 
Town  Development.     (Articles  on  City  Improvement.) 
Trafton,  Science  of  Home  and  Community.     The  Macmillan  Company. 
Ziegler  and  Jaquette,  Our  Community.    J.  C.  Winston  Company. 


THE    SCORE    CARD 


293 


SCORE  CARD.    INTELLECTUAL,  RELIGIOUS,  SOCIAL,  AND  PHYSICAL 
ADVANTAGES   OF  THE  COMMUNITY 


PERFECT 
SCORE 

MY 

SCORE 

INTELLECTUAL  BETTERMENT:  SCHOOLS 
Elementary  schools  within  5  minutes  from  home 
(5);    15  minutes  (4);  too  far  to  walk  ;  free  trans- 
portation (3)  ;  no  free  transportation  (i) 
Secondary  schools  within   15  minutes'  walk  home 
(5)  ;   within  30  min.    (4)  ;    too  far  to  walk  ;   free 
transportation  (3);  no  free  transportation  (i). 
Classical,    technical,    commercial,  and    vocational 
schools  (5).     Take  off  i  for  each  typa  of  school 
not  represented 
Summer  schools  for  time  saving  and  failures  (2) 
Special  schools  for  defectives  (2)  ;  out-of-door  school 
for  tubercular  children   (2)  ;    school  nurse   (2)  ; 
school  clinics  (2) 
College,  technical,  or  normal  schools  in  city  (5)  ; 
within  commuting  distance  (4)  ;  over  thirty  miles 
distant  (i) 
Free  library  system,  with  branches  in  schools  (5)  ; 
without  branches  in  schools  (4)  ;  pay  library  (i) 

35 

INTELLECTUAL  BETTERMENT:  OTHER  SOURCES 
Museums,  —  art,  natural  history,  and  historical,  all 
free  and  well  patronized  (6)  ;  having  pay  days  (5)  ; 
never  free  (3) 
Free  lecture  and  music  courses  (2) 
Free  municipal  band  concerts  (2) 

10 

RELIGIOUS  AND  SOCIAL  BETTERMENT 
Churches,  many  (5)  ;  fair  number  (4)  ;  few  (3) 
Churches  active  in  civic  affairs  (5)  ;   not  active  (o) 
Boy  scouts  (5)  ;    camp  fire  girls  (5)  ;    other  clubs 
active  (2)  ;  not  active  (o) 
Y.  M.  C.  A.,  Y.  W.  C.  A.,  and  other  welfare  organ- 
izations, active  and  well  housed  (5)  ;  poorly  housed 
(3);  inactive  (i) 
Settlement  houses  and  community  centers  (5)  ;  one 
lacking  (3);  none  (o) 

30 

PHYSICAL^BETTERMENT 
Public  parks  with  baseball  fields,  golf  links,  boating, 
tennis  courts,  other  sports  (5).    Take  off  i  for  each 
sport  lacking 
Public  playgrounds  under  supervision  at  all  times 
(5)  ;  part  time  (3) 
Public    playgrounds     equipped    with    basket-ball 
courts,  running  track,  gymnasium,  wading  pool, 
swings,  sandbox  for  children  (5).    Take  off  £  for 
each  point  lacking 
Public  baths  and  bath  houses  free  (3)  ;  small  fee  (2) 
Good  movie  theater  (2);  good  theaters  (2) 
Recreation  centers  for  dances  under  supervision  (3) 

25 

TOTAL 

IOO 

PART   V.      TRANSPORTATION   AND 
COMMUNICATION 

CHAPTER  XIX 
GOOD  ROADS 

Problems.  —  i.  To  learn  something  about  the  history  of 
roads. 

2.  To  learn  the  need  of  good  roads. 

3.  To  understand  how  a  load  is  most  easily  moved. 

4.  To  learn  about  different  road  materials. 

5.  To  understand  the  advantage  that  good  roads  are  to  a 
community. 

Experiments.  —  i.  To  compare  rolling  with  sliding  friction. 

2.  To  explain  inertia. 

3.  To  illustrate  the  advantage  of  large  wheels  for  rough  and  sandy 
roads.  -** 

4.  To  show  the  effect  of  different  grades. 

Project  I.  —  To  INVESTIGATE  AND  REPORT  ON  THE  ROADS  OF  MY 
TOWN. 

Kinds  of  roads  (based  on  material).  What  kind  of  traffic  is  most 
common  on  each.  Cost  of  building.  Cost  of  maintenance.  How 
kept  in  repair.  How  dust  is  taken  care  of.  What  improvements 
seem  advisable. 

Project  II.  —  A   STUDY  OF  THE  ADVANTAGE  IMPROVED  ROADS 

WOULD  BE  TO  MY  CITY  OR  TOWN. 

The  history  of  road  building.  —  Road  building  is  not  a 
new  art,  for  it  has  been  practiced  over  four  thousand  years 

294 


EARLY  AMERICAN  ROADS 


295 


on  the  earth.  The  Romans  were  the  greatest  road  builders 
of  ancient  times,  and  some  of  their  highways  paved  with 
huge  flat  stones  are  in  use  at  the  present  time.  After  the 
fall  of  Rome,  very  few  roads  of  importance  were  built  in 
Europe  for  several 
centuries.  It  was  not 
until  1776  that  France 
began  an  elaborate 
system  of  road  build- 
ing, completing  in  fif- 
teen years  fifteen 
thousand  miles  of 
broken  stone  roads, 
many  of  which  were 
used  for  military  pur- 
poses. About  1815 
Telford  and  McAdam 
in  England  became 
known  through  their 
use  of  broken  stone 

in  road  building.  Our    The   Appian  Way.     An  ancient  Roman    road,  still 

in  good  condition. 

own  macadam  roads 

are  built  after  the  plans  used  by  these  men.  Roads  in  Eu- 
rope are  much  more  numerous,  and,  as  a  rule,  better  built, 
than  those  in  this  country,  and  have  proved  their  value  in 
the  World  War  as  a  means  of  transportation  for  tens  of 
thousands  of  motor  trucks  and  other  vehicles  used  in 
transporting  the  great  armies. 

Early  American  roads.  —  The  earlier  roads  in  America 
were  built  largely  to  help  settle  new  territory  and  to  aid 
the  traders  and  farmers  in  exchanging  their  goods.  The 
first  roads  followed  rivers  or  kept  close  to  the  seaboard. 


296  GOOD  ROADS 

Then  came  the  development  of  post  roads,  for  soon  after 
the  close  of  the  Revolutionary  War  there  were  75  post 
offices  and  over  2000  miles  of  post  roads.  Bridges  were 
of  flimsy  construction  and  built  only  over  small  rivers,  the 
larger  ones  being  crossed  by  ferries.  It  is  interesting  to 
know  that  the  main  wagon  roads  first  built  toward  the 
West,  and  the  railroads  afterward,  followed  the  old  buffalo 
paths  over  the  mountains.  For  example,  in  general,  the 
routes  now  followed  by  the  Baltimore  and  Ohio  R.  R. 
and  Pennsylvania  R.  R.  through  the  Alleghanies  were 
originally  broad  buffalo  paths. 

When  in  the  beginning  of  the  nineteenth  century  it  was 
proposed  that  the  United  States  Government  should  build 
a  national  road  from  the  Atlantic  to  the  Mississippi  River, 
there  was  much  opposition  to  the  scheme,  on  the  ground 
that  thousands  of  men  engaged  in  carrying  people  on 
horseback  would  be  thrown  out  of  employment.  This 
short-sighted  policy,  however,  did  not  prevail,  and  in  1806 
Congress  authorized  a  national  road,  which  was  com- 
pleted about  1838.  Soon  after  this,  railroads  came  into 
existence,  and  as  commodities  could  be  carried  for  long 
distances  more  advantageously  on  them  than  on  roads,  the 
latter  soon  became  largely  local,  centering  around  railroad 
stations  and  towns.  This  condition  continued  until  the 
automobile  began  to  be  widely  used.  People  soon  found 
that  in  order  to  get  the  best  use  from  these  new  machines 
they  must  have  smooth  and  well-made  roads,  so  state  and 
county  taxes  have  been  levied  on  the  owners  of  auto- 
mobiles, so  that,  with  their  assistance,  a  splendid  system 
of  roads  is  coming  into  existence  in  all  parts  of  the  United 
States.  Several  great  national  highways  are  already 
projected  and  have  been  partly  completed,  and  we  shall 


NECESSITY  OF  GOOD   ROADS 


297 


Lincoln  Highway,  a  transcontinental  automobile  road. 

soon  see  this  country  vying  with  Europe  in  the  number 
and  condition  of  its  roads. 

Necessity  of  good  roads.  —  Have  you  ever  thought  that 
the  rural  mail  carriers  in  this  country  travel  over  a  million 
miles  of  road  every  day  in  order  to  carry  news,  messages, 
and  supplies  to  people  who,  a  few  years  ago,  were  cut  off  from 
the  outside  world?  These  mail  carriers  travel  over  some 
of  the  poorest  roads  in  our  country,  in  districts  where  agricul- 
ture is  often  the  only  industry.  The  farmer,  however,  must 
have  good  roads  in  order  to  market  his  crops  and  become  a 
better  citizen  through  contact  with  other  people.  Good 
roads  will  do"  more  toward  making  this  nation  a  unit  in 
thought  and  in  patriotism  than  almost  any  other  one  factor. 

Why  does  the  smooth  road  save  work?  To  lift  a  weight 
requires  work  or  energy.  Every  time  a  wheel  is  pulled  out 
of  a  hole  or  rut,  or  every  time  it  goes  over  a  bump,  a  part 
of  the  load  borne  by  that  wheel  is  unnecessarily  lifted,  and 
work  is  wasted.  This  kind  of  work  is  continually  being  done 


298 


GOOD  ROADS 


on  rough  roads,  and  requires  so  much  more  power  that  a 
horse  or  an  automobile  is  able  to  carry  but  half  the  load 
that  would  be  pos- 
sible on  firm 'and 
smooth  roads. 

Experiment.  —  To  com- 
pare rolling  with 
sliding  friction. 

Materials:  Small  spring  balance.  Small  wheel  cart.  Piece  of  heavy  pape 
somewhat  larger  than  the  cart. 

Method:  (i)  Place  the  cart  on  the  heavy  paper.  Connect  both  the  paper 
and  the  cart  by  a  string  to  the  spring  balance,  in  such  a  way  that  both 
cart  and  paper  will  be  pulled  together.  Hold  the  balance  horizontally 
so  that  the  bar  will  not  bind  on  the  sides.  Drag  them  over  the 
surface  of  the  table. 

(2)  Place  the  heavy  paper  in  the  cart.  Connect  the  hook  of  the 
spring  balance  by  a  string  to  the  cart.  Draw  it  over  the  table.  This 
time  the  wheels  turn. 

Results  and  Conclusion:  In  each  of  the  two  above  cases  note  the  read- 
ing of  the  balance  scale  when  the  load  starts  to  move  and  again  when  it 
is  under  way  and  moving  steadily.     Tabulate  the  results. 
Draw  a  conclusion  from  a  study  of  the  results. 

Use  of  wheels.  —  A  good  many  years  ago  in  this  coun- 
try, Indians  moved  their  loads  about  on  a  kind  of  vehicle 

made  of  two  long 
saplings,  the  ends 
of  which  dragged  on 
the  ground  and  held 
the  load.  To-day 
we  use  wheels  under 
our  load.  The  use 
of  rolling  friction 
instead  of  sliding  friction  marks  a  great  advance  in  moving 
loads.  If  we  had  a  small  cube  of  wood  and  a  small  wooden 


Drawing  a  load  on  two  saplings. 


DRAWING  A  LOAD 


299 


ball  placed  side  by  side  on  the  table,  and  struck  them  each  a 
blow  of  equal  force,  we  know  which  one  would  go  farther. 
A  ball  has  less  surface  touching  the  table,  and  therefore 
there  is  less  friction  to  overcome  when  it  moves.  In  this 
same  way  the  wheel  cart  has  much  less  friction  to  overcome 
than  the  stone  drag  or  the  ox  sled. 

Experiment.  —  To  explain  inertia. 

Materials:  A  5  to  7  pound  weight.  Thread  capable  of  holding  a  10- 
pound  pull. 

Method:  (i)  Suspend  the  weight  by  a  thread.  Connect  a  thread  at  the 
side  A.  Pull  on  this  thread  gently  and  slowly  until  the  weight  has  been 
displaced  several  inches.  Now  bring  the  weight  to  rest.  With  a  quick 
jerk,  pull  on  the  string.  Is  the  weight  moved  as  before  ?  Why  does 
the  string  break? 

(2)  With  the  v/eight  suspended  as  before,  (a)  Pull  with  a  quick  jerk 
downward  on  a  thread  attached  under  the  weight,  at  B.  (b)  Attach  the 
thread  again  and  pull  downward  with  a  slow,  steady  pull.  Why  does 
the  thread  break  below  the  weight  in  (a) 
and  above  the  weight  in  (6)  ? 

Conclusions:  Sum  up  the  conclusions  drawn  in 
each  part  of  this  experiment  and  explain 
inertia  of  rest,  which  is  denned  as  the  tend- 
ency of  a  body  at  rest  to  remain  at  rest. 

Drawing  a  load.  —  Do  you  ever 
wonder  why  it  is  harder  to  start  a 
wagon  than  to  move  it  after  it  is 
started?  It  requires  from  two  to 
eight  times  as  much  force  to  start 
a  load  as  it  does  to  keep  it  in  motion 
after  it  is  started.  This  is  due  to 
what  we  call  inertia,  or  that  tendency 
of  a  body  at  rest  to  remain  at  rest,  or  of  a  body  in  motion  to 
continue  in  motion.  We  have  all  tried  to  stop  a  heavily 
loaded  wagon  and  also  to  start  it.  Extra  force  is  required 
to  overcome  inertia,  to  raise  a  load  from  holes  in  the  road 


3<x>  GOOD  kOADS 

bed,  and  to  increase  the  speed  of  the  vehicle.  All  three 
taken  together  explain  why  so  much  more  force  must  be 
used  to  start  than  to  keep  a  load  moving. 

How  a  load  is  moved.  —  If  a  load  is  drawn  by  hand  it 
is  the  friction  between  your  shoes  and  the  pavement  that 
makes  it  possible  for  you  to  get  a  "  grip  "  and  move  the 
load.  In  the  same  way  the  friction  between  the  horse- 
shoes and  the  pavement  and  the  direct  pull  against  the 
projecting  parts  of  the  wagon  make  it  possible  for  the 
horses  to  move  the  vehicle  forward.  In  the  automobile 
where  the  power  is  inside  the  car,  friction  between  the 
tires  and  the  road  surface  is  depended  upon  to  move  the 
car.  As  the  tire  revolves,  it  pushes  back  on  the  road, 
at  the  same  time  giving  a  forward  thrust  to  the  car  axle, 
and  since  the  road  cannot  be  pushed  back,  the  car  must 
be  pushed  forward. 

Advantage  of  large  wheels.  —  We  have  learned  enough 
of  the  lever  to  understand  why  a  large  wheel  is  better  on  a 
sandy  or  rough  road  than  a  small  one.  Greater  diameter 


What  advantage  has  the  truck  with  large  wheels  over  the  one  with  small  wheels? 

of  the  wheel  gives  greater  leverage,  thus  requiring  less 
force  to  move  the  wheel.  Wheels  of  large  diameter  do 
less  damage  to  a  road  because  they  revolve  more  slowly 
and  pick  up  less  of  the  material  from  the  road.  How- 


RESISTANCE    DUE    TO    GRADE  301 

ever,  wheels  for  vehicles  drawn  by  horses  must  not  be  so 
large  that  the  traces  attached  to  the  horse  are  inclined 
downward,  for  then  part  of  their  power  will  be  lost  in 
pressing  the  wheels  against  the  ground.  Can  you  explain 
this  by  means  of  a  diagram? 

Experiment.  —  To  illustrate  the  advantage  of  large  wheels  for  rough  and 

sandy  roads. 

Materials:   Spring  balance.     Two  small  carts,  one  with  wheels  of  large 
diameter,  the  other  with  wheels  of  small  diameter.    A  long  box  of  dry 
sand.    Weights. 
Method:    Measure  with  the  spring  balance  the  force  required  to  draw 

each  of  these  carts,  loaded  heavily  and  equally,  over  the  sand. 
Conclusion:  From  the  average  results  of  three  trials  draw  a  conclusion. 

Experiment.  —  To  show  the  effect  of  different  grades. 
Materials:  The  small  cart  used  in  the  experiment,  page  298.    A  board 
3  feet  long.     Blocks  to  elevate  one  end  of  the  board.     Spring  balance. 
Method:  Find  the  force  necessary  to  draw  the  cart  in  each  of  four  cases. 

1.  Horizontally 

2.  When  rise  is  i  inch  in  10  inches  (10%  grade) 

3.  When  rise  is  2  inches  in  10  inches         (20%  grade) 

4.  When  rise  is  3  inches  in  10  inches         (30%  grade) 

Results  and  Conclusion:  Record  the  results  in  a  neat  table.     Draw  con- 
clusion and  apply  it  to  a  practical  situation. 

Resistance  due  to  grade.  —  If  we  think  over  the  problem 
of  the  inclined  plane,  we  can  see  why  it  is  that  a  steep 
grade  offers  more  resistance  than  a  gradual  one.  We 
are  lifting  against  gravity.  If  the  road  rises  one  foot  in 
one  hundred,  the  resistance  is  twenty  pounds  per  ton, 
but  if  it  is  one  foot  in  twenty  feet,  the  gravity  resistance 
amounts  to  one  hundred  pounds  per  ton  of  load.  We 
thus  see  that  a  steep  grade  is  bad  in  any  road,  especially 
as  the  smooth  surface  of  a  road  offers  little  foothold  to 
horses.  Where  steep  grades  are  necessary  and  much 
hauling  is  done,  the  hill  should  be  paved  with  stone-block, 


GOOD    ROADS 


Observe  the  steep  road  partly  hidden  by  trees  in  the  upper  picture  and  the  gentle  grade 
of  the  road  in  the  lower  picture. 

or  brick,  so  as  to  give  the  horses  a  foothold.  The  follow- 
ing table l  gives  the  amount  of  load  (in  pounds)  horses 
can  take  on  different  pavements  of  different  grades. 


SURFACE 

LEVEL 

GRADE 

5% 

GRADE 

10% 

Asphalt  .  .  4 

Pounds 

Pounds 

Pounds 

Broken  stone,  best  condition  .  .  . 
Broken  stone,  slightly  muddy  .  .  . 
Broken  stone,  ruts  and  mud  .  .  . 
Earth,  best  condition  

6700 
4700 
3000 

1840 
1500 
1390 

1060 

IOOO 

890 

Earth,  average  condition  .... 
Stone-block  pavements,  dry  and  clean 
Stone-block  pavements,  muddy  .  . 
Sand,  wet  

1400 
8300 
6250 

900 
1920 
1800 
621; 

660 

lOQO 
IO4O 
?QO 

Sand,  dry  

1087 

Table  from  Highway  Construction,  Byrne,  Am.  Tech.  Soc. 


ROAD  BUILDING  MATERIALS 


303 


Road  making.  —  In  this  country,  the  method  of  Telford 
and  McAdam  is  used  most  commonly  in  making  roads. 


Cross-section  of  macadam  road. 

First,  the  road  is  excavated  to  a  depth  of  two  or  three 
feet,  and  several  layers  of  large  stones  are  placed  at  the 
bottom  of  the  excavation.  These  are  covered  by  other 
layers  of  smaller  stone,  and  still  smaller  on  these,  the 
particles  becoming  finer  as  they  come  toward  the  sur- 
face, until  the  surface  of  the  road  is  made  of  a  fine  stone 
dust.  The  road  is  then  covered  with  asphalt  or  tar,  or 
bituminous  material  as  the  binder.  This  sticky  material 
running  in  between  the  stones  holds  them  in  place.  The 
road  is  a  little  higher  in  the  middle  than  on  the  sides  for 
the  purpose  of  drainage. 

Other  road  building  materials.  —  In  cities  where  there 
is  much  hauling  of  loads  by  horses,  cobblestones  of  granite 
or  sandstone,  vitrified  brick,  or  wood  blocks  are  used. 
Brick  makes  a  good  paving  for  both  level  and  hilly  roads, 
is  durable,  and  resists  the  action  of  water  and  frost.  Wood 
blocks  have  to  be  treated  with  creosote  in  order  to  pro- 
tect them  from  decay.  They  are  laid  on  a  concrete  or 
cement  foundation  and  bound  together  with  tar.  They 
are  comparatively  noiseless,  and  are  excellent  for  use  in 
city  streets. 


3°4 


GOOD  ROADS 


Use  of  concrete.  —  In  late  years  a  number  of  our  best 
roads  are  being  made  of  concrete.  They  are  made  in  huge 
blocks  with  a  little  area  between  the  blocks  in  which  asphalt 

or  some  expansive  filler 
is  placed  so  that  the 
action  of  frost  and  heat 
with  the  alternating  con- 
traction and  expansion 
will  not  destroy  the  sur- 
face. These  roads,  if 
built  deep  enough,  are 
practically  indestructi- 
ble, and  thus  cheaper  in 
the  end  than  almost  any 
other  kind  of  road. 

What  is  the  best  road 
surface  to  have  ?  —  This 
A  concrete  road.  question   would   be   an- 

swered  best  by  deter- 
mining the  use  of  the  road  and  the  place  where  the  pave- 
ment is  laid.  Granite  block  is  most  durable  for  heavy 
loads,  but  is  the  most  noisy.  Brick  is  less  rough  and 
less  noisy,  but  goes  to  pieces  under  heavy  traffic. 
Wood  blocks  are  pleasing  in  appearance,  and  quiet,  but 
slippery  in  wet  weather,  and  difficult  to  keep  clean. 
Asphalt  cracks  in  severe  cold  and  becomes  soft  and 
wavy  under  extreme  heat.  Macadam  gives  a  good 
foothold  to  horses,  and  is  a  good  appearing  road,  but 
needs  constant  attention  to  keep  it  in  repair.  Concrete 
and  cement  are  pleasing  in  appearance,  durable,  and 
probably  best  for  general  traffic,  though  they  give 
little  foothold  for  horses  up  grade. 


DUST   IN  THE  COMMUNITY 


305 


Result  of  water  action  on  a  road.    The  road  might 
have  been  saved  by  small  repairs  made  earlier. 


An  interesting  project  would  be  a  study  of  the  roads 
of  your  community  with  respect  to  their  efficiency, 
durability,  and  use- 
fulness for  the  pur- 
poses for  which  they 
are  used.  Find  out 
how  many  different 
kinds  of  roads  there 
are,  and  the  reasons 
why  these  roads  were 
built  in  these  par- 
ticular places. 

Destruction  of 
roads  by  traffic. 
-When  an  automobile  or  other  wheeled  vehicle  goes 
rapidly  over  a  road,  a  partial  vacuum  is  produced 
behind  the  wheels,  which  have  a  tendency  to  pull  up 
materials  from  the  road  bed.  The  rush  of  air  into 
the  partial  vacuum  carries  small  loose  particles  which 
have  been  displaced  by  the  tires  of  automobiles  or  hoofs 
of  horses.  This  continual  withdrawal  of  dust  and  other 
small  particles  finally  loosens  large  fragments,  and  so  a 
road  with  its  surface  full  of  holes  is  produced.  Cement  or 
block  pavement  obviates  this  difficulty  to  a  large  extent. 

Dust  in  the  community.  —  One  of  the  evils  a  community 
must  fight  is  dust.  We  have  all  seen  street  cleaners  in  a 
large  community,  but  in  a  small  place  we  do  not  always 
have  street  cleaners  and  street  cleaning  machines,  therefore 
we  must  have  other  means  of  getting  rid  of  dust.  Sometimes 
we  have  sprinkling  carts,  or  the  hose  from  the  hydrant  is 
played  on  the  street.  Sometimes  oil  or  a  mixture  of  tar  and 
oil  is  sprayed  over  the  road.  This  keeps  down  the  dust,  but 

H.  W.  CIV.  SCI.  COMM. 20 


306  GOOD  ROADS 

comes  into  our  houses  on  our  shoes,  and  gets  on  our  clothes. 
It  is  far  better  for  a  community  to  have  the  road  surfaces 
covered  with  asphalt,  bitumen,  or  concrete. 

How  roads  may  beautify  our  community.  —  No  town 
nowadays  should  be  allowed  to  grow  in  a  haphazard  way. 
It  should  be  planned,  the  main  business  streets  being  made 
wide  enough  for  future  growth,  and  trees  and  shrubs  should 
be  put  out  in  abundance.  The  principal  commercial  street 
should  be  at  least  eighty  feet  wide,  with  sidewalks  having 
a  width  of  twenty  feet.  In  the  residential  districts  we 
should  have  streets  at  least  forty  feet  in  width,  with  ten- 
foot  sidewalks.  Boston  has  only  26  per  cent  of  its  area  de- 
voted to  streets,  while  Duluth,  Minnesota,  has  33  per  cent. 
We  should  have  some  winding  streets,  as  these  tend  to  break 
up  the  monotony  of  streets  running  at  right  angles.  Parks 
should  be  planned,  and  plenty  of  small  squares.  The  city  of 
Washington  has  numerous  circles  with  broad  avenues  run- 
ning diagonally  to  the  main  street  of  the  city,  giving  it  a 
most  pleasing  appearance,  for  one  is  constantly  coming  to 
small  parks  in  passing  from  one  part  of  the  city  to  another. 

City  planning. — Most  modern  cities  are  planned  with  an 
eye  to  future  growth.  Boston  and  other  old  New  England 
towns  have  grown  up  with  no  idea  of  future  development, 
while  cities  like  Philadelphia  and  Washington  were  planned 
from  the  very  beginning.  The  beauty  of  a  city  is  a  very 
practical  asset  and  most  cities  have  come  to  realize  this. 
Streets  are  built  with  provision  for  wide  sidewalks  and 
shade  trees.  The  laying  out  of  boulevards  and  drives  to 
take  advantage  of  natural  scenery,  as  well  as  the  planning 
of  roads  to  facilitate  business,  is  an  important  part  of  a  city 
planning  board's  duties.  Old  cities  are  helped  in  many 
cases  by  a  vigorous  program  of  street  widening.  This 


CITY  PLANNING 


307 


usually  necessitates  the  removal  of  many  old  buildings, 
but  improvement  often  demands  drastic  action. 


Trees  are  frequently  injured  and  eventually  destroyed  in  making  room  for  electric 
wires  and  poles  along  narrow  streets. 


REFERENCE  BOOKS 

Articles  on  Good  Roads.    The  American  City. 

Bishop  and  Keller,  Industry  and  Trade.     Ginn  and  Company. 

Farmers'  Bulletin  338,  Macadam  Roads.    U.  S.  Dept.  of  Agriculture. 

Hall,  Wonders  of  Transport.    Dodge  Publishing  Company. 

Hughes,  Community  Civics.     Allyn  and  Bacon. 

Judson,  Road  Preservation  and  Dust  Prevention.     (For  teachers.)    Engineering  News 

Publishing  Company. 

Page,  Roads,  Paths  and  Bridges.     (For  teachers.)     Sturgis  and  Walton  Company. 
Portland  Cement,  Roads,  Concrete  and  Cement.     6  pamphlets.     Philadelphia,  1915. 
Rocheleau,  Great  American  Industries,  Transportation.    Flanagan  and  Company. 
Smith  and  Jewett,  Introduction  to  the  Study  of  Science.     The  Macmillan  Company. 
Tappan,  Children's  Hour.    Vols.  14,  15.    Houghton  Mifflin  Company. 
Thompson,  Concrete  in  Highway  Construction.     Atlas  Portland  Cement  Company. 
Trafton,  Science  of  Home  and  Community.     The  Macmillan  Company. 
Van  Buskirk  and  Smith.  The  Science  of  Everyday  Life.     Houghton  Mifflin  Company. 
Wilkinson,  Practical  Agriculture.     American  Book  Company. 
Ziegler  and  Jaquette,  Our' Community.    J.  C.  Winston  Company. 


CHAPTER  XX 
TRANSPORTATION  BY  WATER 

Problems.  —  i.  To  learn  how  water  transportation  began 
and  developed. 

2 .  To  understand  why  things  float. 

3.  To  learn  how  steam  was  successfully  applied  to  drive 
boats. 

4.  To  understand  how  submarines  are  managed. 

5.  To  know  tJie  principal  water  trade  routes  of  the  world. 

Experiments.  —  i.  To  see  how  much  water  floating  bodies  displace 
(volume  and  weight). 

2.  To  see  how  much  weight  sinking  bodies  lose  in  water. 

3.  To  explain  center  of  gravity  and  center  of  buoyancy. 

4.  To  show  how  the  submarine  may  rise  and  sink  in  water.     (Cartesian 
diver.) 

Project  I.  —  To  BECOME  A  SKILLED  MOTOR  BOAT  OPERATOR. 

One  must  understand  the  principles  of  the  engine,  propeller,  rudder, 
flotation:  the  care  of  engine  and  of  the  boat  in  water  and  out  of 
water. 

Project  II.  —  To  BECOME  EXPERT  IN  HANDLING  A  SAIL  BOAT  OR 
ICE  BOAT. 

Project  in.  —  To  MAKE  A  TOY  SAIL  BOAT,  POWER  BOAT,  SUB- 
MARINE OR  PERISCOPE. 

Development  of  water  transportation.  —  Long  after  the 
land  was  used  as  a  means  of  transportation,  primitive  man 
must  have  developed  the  idea  of  going  over  streams  or 
bodies  of  water  on  logs  or  other  floating  objects.  It  was 

308 


WHY  THINGS  FLOAT  309 

a  long  step  to  the  hewing  down  of  the  tree  and  cutting  a 
canoe  out  of  a  hollow  log,  and  still  a  longer  period  elapsed 
before  large  vessels  such  as  the  triremes  and  galleys  of  the 
Romans  and  Greeks  were  developed.  Then  men  began  to 
use  the  wind  for  locomotion  on  the  water,  but  he  still 
used  oars  when  winds  were  unavailable.  The  Middle 
Ages  saw  the  development  of  sailing  vessels  and  Spain's 
and  then  England's  supremacy  on  the  sea.  It  was  cen- 
turies after  the  discovery  of  the  new  world  that  the  appli- 
cation of  steam  was  first  made  in  the  clumsy  inventions  of 
Fitch  and  others  who  used  steam  to  move  a  number  of 
oars  or  paddles.  Then  came  Fulton's  triumph  with  a 
paddle-wheel  boat.  To-day  the  ocean  liner  is  moved  by 
turbines  turning  one  or  even  four  screws  which  propel 
vessels  over  900  feet  long,  disp  lacing  60,000  tons  of  water. 
One  hundred  and  fifty  years  ago  a  month  was  considered 
good  time  on  a  sailing  vessel  between  England  and  this 
country.  To-day  our  best  liners  make  this  distance  in 
about  five  days. 

Why  things  float.  —  A  great  many  years  ago  the  famous 
old  mathematician,  Archimedes,  is  said  to  have  discovered 
the  significance  of  what  we  now  call  density.  The  story 
goes  that  King  Hiero  of  Sicily  had  a  crown  made  by  one 
of  his  goldsmiths  which  he  suspected  did  not  contain  pure 
gold.  He  asked  Archimedes  to  discover  if  the  crown  had 
been  made  of  mixed  metals,  but  would  not  allow  him  to 
bore  into  it  or  mar  it  in  any  way  to  find  out.  The  philos- 
opher, while  taking  a  bath  one  day,  noticed  that  his  body 
displaced  a  certain  amount  of  water,  and  seemed  to  be 
buoyed  up  by  it.  He  was  so  impressed  by  this  that  he 
applied  the  idea  to  the  crown,  and  thinking  that  he  had 
found  the  solution  of  his  problem,  he  rushed,  philosopher- 


TRANSPORTATION  BY  WATER 


like,  from  his  bath  without  thinking  of  clothes,  and  ran 
down  the  street  crying,  "  Eureka !  Eureka !  "  which  means, 
"  I  have  found  it !  I  have  found  it !  "  He  had  really 
found  the  solution  of  his  problem.  By  weighing  tlie  crown 
in  the  air,  then  in  water,  he  found  how  much  it  lost  when 
weighed  in  water.  This  loss  was  due  to  the  buoyancy  of 
the  water  and  was  equal  to  the  weight  of  water  displaced. 
The  volume  of  the  water  displaced  was  of  course  the  volume 
of  the  crown.  The  weight  divided  by  its  volume  gave  its 
density,  since  density  is  the  weight  of  a  unit  volume.  The 
density  of  pure  gold  being  known  it  was  an  easy  matter  to 
compare  the  density  of  the  crown  with  that  of  pure  gold 
and  so  detect  any  fraud  of  mixing  lighter  metals  with  the 
very  heavy  metal  gold.  The  principle  of  buoyancy  thus 
discovered  is  stated,  "  A  body  immersed  or  floating  in  a 
fluid  is  buoyed  up  with  a  force  equal 
to  the  weight  of  the  fluid  displaced." 

Experiment.  —  To  see  how  much  water  a  float- 
ing body  displaces  (volume  and  weight). 
Materials:   Overflow  can  and  catch  bucket. 
Spring    balance.     A    floating    block    of 
wood.     Thread. 

Method:  Fill  the  overflow  can  until  some 
water  runs  out  the  spout.  When  all 
has  stopped  running  out,  weigh  the  empty 
catch  bucket  and  place  it  under  the  spout. 
Weigh  the  dry  block.  Lower  the  block 
into  the  can.  Weigh  the  bucket  and 
water  which  was  displaced  by  the  block. 

Result:  How  much  water  did  the  block  displace  ?  Compare  this  with  the 
weight  of  the  block.  Does  the  same  relation  hold  in  trials  with  other 
floating  bodies? 

Conclusion:  What  do  you  conclude  is  the  weight  of  water  displaced  by  a 
floating  body,  stated  in  general  terms?     Does  a  floating  body  displace 
its  own  volume  of  water? 
Application:  What  is  meant  by  the  displacement  of  a  ship? 


STABILITY 


Experiment.  —  To  see  how  much  weight  sinking  bodies  lose  in  water. 

Materials:  Overflow  can.  Catch  bucket.  Spring  balance.  A  solid 
glass  stopper.  A  rock.  Thread. 

Method:  Weigh  the  glass  stopper  in  air.  Fill  overflow  can  to  the  proper 
level.  Suspend  glass  stopper  by  thread  in  water  in  the  overflow  can 
catching  the  overflow  and  at  the  same  time  weighing  the  stopper.  Find 
weight  of  the  water  displaced  and  the  loss  of  weight  of  the  stopper. 
Repeat  the  experiment  with  the  rock  in  place  of  the  stopper. 

Result  and  Conclusion:  Compare  the  loss  of  weight  of  the  body  when 
weighed  in  water  with  the  weight  of  the  water  displaced.  What  do 
you  conclude? 

Note:  Knowing  that  the  volume  of  water  displaced  equals  the  volume 
of  the  immersed  body,  s  ggest  a  way  for  finding  the  volume  of  an  ir- 
regularly shaped  body. 

Buoyancy.  —  When  we  say  a  substance  is  buoyant  we 
simply  mean  that  it  is  lighter  than  the  same  bulk  of  water, 
and  therefore  floats.  The  force  which  water  exerts  in 
holding  up  the  weight  of  a  body,  no  matter  whether  this 
weight  sinks  or  remains  on  the  surf  ace,  is  called  the  buoyant 
force  of  water.  This  is  equal  to  the  weight  of  the  water 
displaced.  Boat  builders  knowing  the  densities  of  different 
materials  and  the  form  of  ship  to  be  built  can  calculate 
quite  easily  its  displacement.  The  following  table  shows 
the  densities  of  some  common  substances. 


SUBSTANCES 

DENSITY 

Pounds  per 
cubic  foot 

RELATIVE 
DENSITY 

Specific 
gravity 

SUBSTANCES 

DENSITY 

Pounds  per 
cubic  foot 

RELATIVE 
DENSITY 

Specific 
gravity 

Water      .  r 

62.5 

i. 

Glass 

162 

2.6 

Cork    .     . 

IS 

.25 

Aluminum 

166 

2.65 

Cedar       . 

35 

•4 

Iron     .     .     . 

470 

7-5 

Pine     .     . 
Oak     .     . 

29 

S3 

j 

Lead    .     .     . 
Gold         .     . 

710 
1205 

11.4 
19-3 

Stability.  —  We  all  know  the  danger  of  being  careless 
in  a  canoe  or  a  narrow  row  boat,  for  if  we  go  too  far  on  one 
side  and  raise  the  body  too  high  above  the  surface  of  the 


312  TRANSPORTATION  BY  WATER 

water,  we  may  suddenly  find  ourselves  in  the  water  with 
an  upset  canoe  or  boat.  The  reason  for  this  is  that  we  have 
changed  the  positions  of  both  the  center  of  gravity  and  the 
center  of  buoyancy.  The  center  of  gravity  of  a  body  is  a 
point  in  that  body  about  which  the  entire  mass  seems  to 
be  centered.  The  center  of  buoyancy  is  the  center  of 
mass  of  that  part  of  the  boat  which  is  below  the  water 
line  or  it  is  the  center  of  the  space  from  which  water  is 
displaced. 

When  a  person  sits  close  to  one  side  of  a  boat  that  side 
sinks  deeper  into  the  water  and  the  center  of  buoyancy  is 
shifted  toward  that  side.  The  center  of  gravity  of  the 


The  lower  arrow  represents  buoyant  force,  the  upper  arrow,  gravity  force.  In  a  these 
are  in  the  same  vertical  line  and  the  boat  is  in  stable  equilibrium.  In  b  and  c,  the 
boat  is  shown  in  unstable  equilibrium.  What  will  be  the  next  movement  of  the 
boat  in  6?  in  c? 

person  and  boat  also  moves  toward  the  side.  If  the  new 
center  of  gravity  is  between  the  new  center  of  buoyancy  and 
the  keel,  the  boat  will  become  stable,  but  if  it  is  between 
the  center  and  the  side  of  the  boat  it  will  upset.  (See 
diagram.)  A  high  center  of  gravity  will  cause  an  upset 
quicker  than  a  low  center  of  gravity.  Can  you  tell  why? 
Boat  builders  in  order  to  keep  the  center  of  gravity  low  add 
a  keel  weighted  with  lead,  take  on  a  heavy  load  of  ballast, 
or  fill  tanks  with  water  close  to  the  bottom  of  the  boat. 


ROWING 


313 


Experiment.  —  To  explain  center  of  gravity  and  center  of  buoyancy. 

Materials:  A  piece  of  heavy  cardboard  or  thin  board  cut  in  the  shape  of 
figure  in  accompanying  diagram.  A  large  pin.  A  plumb  line.  Shears. 
Gummed  paper.  A  piece  of  lead. 

Method:  (i)  Center  of  gravity.  Make  two  holes  as  indicated  at  A  and  B. 
Support  the  cardboard  and  plumb  line  on  the  pin  at  A.  Make  a  line 
across  the  cardboard 
to  coincide  with  the 
plumb  line.  The  cen- 
ter of  gravity  must 
be  some  point  in  this 
line.  Repeat,  using 
B  as  the  point  of  sup- 
port. The  center  of 
gravity  must  be  in 
this  second  line  deter- 


mined by  the  plumb 

line.  Can  you  mark  the  point  which  represents  the  center  of  gravity? 
Label  it  Gi.  Attach  a  piece  of  lead  to  K  to  represent  a  heavy  keel. 
Find  the  center  of  gravity  as  before.  Label  it  £2. 

(2)  Center  of  buoyancy.  Draw  a  line  across  the  cardboard  to  repre- 
sent the  water  line.  (See  figure.)  Cut  the  cardboard  on  this  line.  The 
lower  portion  represents  that  part  of  the  boat  under  water.  The 
center  of  gravity  of  that  portion  of  a  body  immersed  in  water  is  the 
center  of  buoyancy.  Find  the  center  of  gravity  (center  of  buoyancy) 
of  this  portion  without  the  lead  as  in  (i),  label  this  Bi.  Use  a  and  b 
as  points  of  support.  Attach  the  lead  to  the  keel  and  repeat,  label  the 
center  of  gravity  (center  of  buoyancy),  B 2. 

Application:  Place  the  two  parts  together.  Note  the  change  in  position 
of  center  of  gravity  (Gi  and  G2)  and  center  of  buoyancy  (Bi  and  Bz) 
which  resulted  from  adding  the  lead  keel.  When  the  lead  is  used  is 
there  less  or  more  danger  of  upsetting  the  boat?  Explain. 

Rowing.  —  The  first  power  used  in  water  transportation 
was  probably  a  pole.  Then  came  the  paddle.  We  all  have 
read  of  the  wonderful  skill  of  the  North  American  Indian 
with  his  light  birch  bark  canoe.  But  the  paddle  would  not 
do  for  heavy  loads.  Here  came  the  use  of  oars,  an  oar 
being  used  as  a  lever,  applied  at  the  oarlock  to  the  weight 
to  be  moved,  while  the  blade  of  the  oar  acted  as  a  ful- 


TRANSPORTATION   BY  WATER 


crum.  A  stroke  against  the  water  would  pull  the  boat 
forward  a  little  and  the  oar  would  be  lifted  from  the  water, 
sent  back  through  the  air  where  there  was  little  resistance, 

and  again  another  pull 
would  bring  the  boat 
forward. 

Sailing.  —  The  boats 
in  ancient  times  were 
always  provided  with 
oars,  sometimes  as  many 

Explain  lever  action  here.  ag    tkree    rows    of    slaves 

being  used  to  propel  a  great  Roman  trireme.  But  with  an 
understanding  of  the  laws  of  physics  came  the  use  of  sails. 
When  the  wind  meets  a  sail  at  right  angles  its  full  force 
tends  to  move  it.  When  the  angle  between  the  wind  and 
sail  is  oblique  a  part  of  the  wind  spills  over  the  side  so  that 


WIND 


only  a  portion  of  the  force  of  the  wind  is  effective  in 
moving  the  boat.  The  law  which  applies  to  this  is 
known  as  the  law  of  ilie  resolution  of  forces.  This  will  be 
explained  to  you  in  a  future  course  in  physics.  By 
shifting  the  sail  and  letting  the  wind  work  on  one  side 


USE  OF  STEAM 


315 


and  then  on  the  other  and  thus  make  a  zigzag  course  it  is 
possible  to  sail  against  the  wind.  This  is  known  as ' '  tacking." 
Use  of  steam.  —  In  the  latter  part  of  the  eighteenth 
century,  men  began  to  experiment  with  steam  as  a  motive 
power  for  boats.  A  man  named  Fitch  rigged  up  paddles 
along  the  sides  of  a  small  boat  and  by  means  of  an  engine 
drove  it  through  the  water  at  the  rate  of  seven  and  one-half 
miles  an  hour,  but  it  was  the  good  fortune  of  Robert  Fulton 
to  make  the  first  serviceable  steamboat.  He  had  become 
interested  in  the  steam  engine  while  studying  painting  in 
Paris,  and  in  1803  made  a  small  steamboat  which  he 
successfully  operated  on  the  River  Seine.  He  tried  to 
enlist  the  interest  of  Napoleon  in  this  boat.  A  committee 
was  appointed  to  see  it  work,  but  on  the  morning  of  the 
trial,  Fulton  went  to  the  boat  and  found  to  his  dismay  that 
the  heavy  engine 
had  broken  through 
the  boat  and  was 
lying  on  the  bottom 
of  the  river.  In 
1806,  however,  Ful- 
ton purchased  an 
engine  in  England, 
built  his  boat  on 
the  Hudson,  and 
announced  that  on  a 
certain  day  it  would 
begin  its  trip  to  Albany.  Crowds  of  people  lined  the 
wharves  and  the  river  banks,  most  of  them  expecting  that 
the  trial  would  fail,  but  when  they  saw  the  Clermont,  as 
it  was  called,  move  out  under  perfect  control  of  the  engineer, 
they  realized  that  a  new  epoch  had  begun  in  transportation 


The  Ckrmont  compared  with  the  Hudson  River  boats 
of  to-day. 


TRANSPORTATION  BY  WATER 


on  water.  The  boat  made  a  successful  trip  to  Albany  in 
thirty-two  hours,  while  the  ordinary  sailing  vessels  took 
about  four  days.  Rapid  development  of  the  steamship 
followed,  so  that  by  1858  we  had  a  record  breaking  ship  for 
size  in  the  Great  Eastern,  a  boat  692  feet  long,  83  feet 
wide,  and  58  feet  deep.  She  was  driven  by  paddle  wheels 
and  propellers,  and  rendered  great  service  in  laying  the 
first  transatlantic  submarine  cable.  Unfortunately  she 
was  so  far  in  advance  of  her  time  that  she  was  not  a  success 


SLA  CK-fferOLWA/G  BLADES 


HW/r£-S7XT/OWAfiY BLADES 


The  stationary  and  revolving  blades  are  so  arranged  that  the  force  of  the  steam  causes 
the  inner  blades  and  spindle  to  which  they  are  attached  to  revolve.  This  revolving 
spindle  is  supported  by  bearings  BE  and  the  axle  of  a  machine  operated  by  the  tur- 
bine attached  at  A. 

commercially.  At  the  time  of  the  Civil  War,  iron  came  into 
use  in  the  making  of  ships'  hulls,  and  now  as  we  know,  steel 
has  come  into  extensive  use  and  even  concrete  is  being  used. 
The  modern  greyhounds,  such  as  the  Aquitania,  the 
Lusitania  of  unfortunate  fame,  and  the  Olympic,  the 
latter  890  feet  in  length,  give  one  some  idea  of  modern 
transportation  in  water.  They  have  two,  three,  or  four 


THE   SUBMARINE 


317 


screw  propellers,  thus  enabling  more  rapid  turning  in  a 
limited  area.  The  steam  engine,  too,  has  taken  wonderful 
strides.  The  latest  type  is  the  so-called  steam  turbine, 
which  was  first  used  by  Sir  Charles  Parsons  in  1897.  With 
this  type  of  engine,  a  speed  of  forty  miles  an  hour  is  obtain- 
able as  against  twenty-five  or  thirty  miles  with  an  ordinary 
steam  engine.  One  serious  disadvantage  of  the  turbine 
is  the  fact  that  it  cannot  be  reversed,  so  that  separate 
turbines  have  to  be  made  for  reversing  the  ship. 

Electricity  as  a  motive  power.  —  One  interesting  develop- 
ment which  is  being  applied  to  our  latest  battleships  is  the 
attachment  of  the  turbine  to  electric  generators,  these 
generators  being  used  to  drive  motors  which  turn  pro- 
pellers. Reversal  of  the  electric  motors  does  not  interfere 
with  the  working  of  the  turbine,  and  very  rapid  manipu- 
lation of  a  ship  is  thus  obtained. 

The  submarine.  —  The  World  War  brought  the  submarine 


Section  of  Holland  submarine. 


into  notoriety,  and  caused  its  rapid]  development.  A 
submarine  is  made  so  that  its  weight  is  a  little  less  than  the 
weight  of  its  own  volume  of  water.  Along  the  sides  are 
numerous  air-tight  tanks.  Water  is  admitted  to  these 
tanks  and  forced  from  them  by  the  use  of  compressed  air. 
In  this  way  the  boat  may  be  made  to  sink  to  any  depth 
and  come  to  surface  again.  By  use  of  horizontal  rudders 


TRANSPORTATION  BY  WATER 


the  boat  can  be  made  to  dive  or  come  up,  depending  on 
the  way  in  which  the  rudder  is  operated.  When  on  the 
surface,  the  submarine  usually  employs  a  Diesel  oil  engine. 
During  this  time  it  generates  electricity  for  a  large  number 
of  storage  batteries.  When  under  water  it  moves  by  means 
of  the  power  stored  in  these  cells.  The  storage  batteries  also 
furnish  current  for  lighting.  Some  of  the  German  subma- 
rines captured  in  the  late  war  were  over  300  feet  long,  and 
submarines  planned  for  our  navy  before  the  Disarmament 
Conference  was  called  were  to  be  even  longer  than  this. 

Experiment.  —  To  show  how  the  submarine  may  rise  and  sink  in  water. 

Materials:  A  glass  cylinder  fitted  with  a 
i-hole  stopper.  Glass  and  rubber  tubing. 
A  pill  vial. 

Method  and  Result:  Pass  a  3-inch  length  of 
glass  tubing  through  the  stopper.  Attach 
rubber  tubing  to  the  glass  tube.  Fill  the 
cylinder  nearly  full  of  water.  Fill  the  vial  \ 
full  of  water  and  drop  it  mouth  downward 
into  the  water.  If  it  sinks,  remove  enough 
water  from  the  vial  so  that  it  will  just  float. 
Close  the  cylinder  with  the  stopper  and  blow 
through  the  tube.  If  the  vial  does  not  sink 
add  a  little  more  water  to  it.  Change  the 
amount  of  water  in  the  vial  until  it  is  so  ad- 
justed that  upon  blowing  into  the  closed 
cylinder  the  vial  sinks  and  upon  releasing 
the  pressure  it  rises.  Watch  carefully  the 

change  in  water  space  and  air  space  in  the  vial.     Account  for  the  sink- 
ing and  rising. 

Application:    Explain  one  way  for  making  a  submarine  sink  or  rise  in 
water. 

The  periscope.  —  Another  invention  which  made  the 
submarine  the  dangerous  menace  that  it  was  is  the  peri- 
scope. A  study  of  the  diagram  will  show  how  this  periscope 
could -be  used.  Light  from  objects  on  the  surface  is  trans- 


SEASONAL  CHANGES  IN   TRADE  ROUTES        319 


mitted  through  this  instrument  by  an  arrangement  of  lenses 
and  mirrors,  so  that  the  person  at  the  wheel  of  a  submarine 
can  see  all  that  is  taking 
place  about  him,  and  the 
torpedo  can  be  directed 
toward  its  mark. 

Ocean  trade  routes.  —  A 
study  of  a  trade  route  map 
shows  that  the  principal 
trade  routes  on  the  Atlantic 
Ocean  run  from  England 
or  continental  ports  chiefly 
to  New  York,  but  some  to 
Boston  and  Canadian  ports. 
Other  routes  extend  to 
South  America  around  Cape 
Horn  and  the  Cape  of  Good 
Hope,  while  in  the  Pacific 
Ocean  the  chief  trade  routes 
are  from  San  Francisco  to 
Japan,  Australia,  and  New 
Zealand,  and  to  the  East 
Indies  and  Philippine  ports. 
The  opening  of  the  Panama 
Canal  with  its  enormous  locks  and  electric  towing 
system  has  made  important  changes  in  trade  routes  from 
Atlantic  to  Pacific  ports.  Much  time  is  saved,  especially 
from  England  to  San  Francisco,  Japan,  and  Australia. 

Seasonal  changes  in  trade  routes.  —  Since  the  ocean 
is  free  to  the  world  the  main  routes  of  travel  are  fixed  by 
international  agreement,  and  especially  in  the  North  Atlan- 
tic Ocean  where  many  ships  pass,  these  routes  serve  as 


The  periscope  is  the  eye  of  the  submarine. 
Explain. 


320  TRANSPORTATION  BY  WATER 

double  tracks  on  a  railway.  All  boats  moving  from  Europe 
to  American  ports  are  required  to  keep  between  certain 
degrees  of  latitude,  and  boats  moving  from  American  ports 
to  Europe  between  certain  other  degrees  of  latitude.  These 
trade  routes  move  with  the  seasons,  for  during  the  summer 
months  great  icebergs  float  down  from  Greenland  and 
become  a  menace  to  navigation.  We  still  remember  the 
awful  Titanic  disaster  where  nearly  a  thousand  lives  were 
lost.  To  avoid  a  recurrence  of  such  a  catastrophe,  in  the 
summer  time  ships  pass  far  to  the  south  of  Newfoundland, 
while  in  the  winter  they  take  a  much  shorter  course, 
passing  by  the  southern  end  of  that  island. 

Government  aids  in  navigation.  —  Since  a  great  part  of 
our  freight  is  carried  on  water,  because  this  is  a  cheaper 
method  of  transportation,  governments  have  come  to  take 
care  that  all  dangers  to  navigation  are  carefully  charted 
and  marked.  These  marks  are  called  buoys.  Some  of 
them  are  equipped  with  whistles  to  warn  one  of  danger ; 
some  mark  channels  and  are  often  provided  with  lights  at 
night.  Then  we  have  great  lighthouses  with  lights  capable 
of  being  seen  from  thirty  to  forty  miles  distant.  Life 
saving  stations  are  located  on  dangerous  parts  of  our  coast 
and  during  a  storm  men  constantly  patrol  the  shore  so  as 
to  render  quick  aid  in  case  of  a  wreck. 

Canals  as  waterways.  —  In  early  days  before  the  rail- 
roads, rivers  were  of  much  importance  as  a  means  of  trans- 
portation. Then  came  a  period  roughly  from  1820  to  1840 
when  canals  were  built  in  great  numbers,  over  4468  miles 
being  ultimately  built.  Most  of  these  canals,  however, 
were  destined  to  failure  when  the  railroads  entered  com- 
petition with  them.  The  Erie  Canal  with  its  363  miles 
of  waterway,  the  Chesapeake  and  Ohio  Canal,  and  a  few 


INLAND  WATERWAYS  321 

others  are  still  in  existence.  Of  much  importance  is  the 
more  recent  Barge  Canal  in  New  York  state.  This  was 
completed  in  1918  and  has  a  capacity  for  boats  several  times 
the  size  of  the  canal  boats  used  on  the  old  Erie  Canal.  Our 
modern  achievement  in  the  digging  of  the  Panama  Canal 
is  one  which  we  can  well  afford  to  be  proud  of  as  a 


The  Panama  Canal  saves  8000  miles  in  a  water  trip  from  the  Atlantic  to  the  Pacific 

coast. 

nation.  One  of  the  most  notable  undertakings  of  modern 
engineering  is  that  of  the  Marseilles-Rhone  Canal  in 
France,  where  not  only  has  the  canal  followed  this  river, 
but  part  of  its  route  actually  cuts  through  a  range  of 
mountains  with  a  tunnel  about  5  miles  long  and  77.5  feet 
wide  by  47.5  feet  high. 

Inland  waterways.  —  The  development  of  North  America 
has  been  greatly  influenced  by  its  splendid  inland  water- 

H.  W.  CIV.  SCI.  COMM.  —  21 


322  TRANSPORTATION  BY  WATER 

ways.  Not  only  have  we  several  great  river  systems 
navigable  for  thousands  of  miles,  but  the  chain  of  the 
Great  Lakes  forms  a  cheap  and  easy  means  of  transport 
for  ore  and  grain.  In  addition,  Canada  and  the  United 
States  have  built  great  canals  with  locks  at  the  "  Soo  " 
and  between  Lake  Erie  and  Ontario,  and  the  United  States 
has  dredged  a  wide  ship  channel  through  the  shallow  waters 
of  Lake  St.  Clair.  The  yearly  tonnage  through  the  "  Soo  " 
locks  is  greater  than  that  in  any  other  canal  in  the  world. 

REFERENCE  BOOKS 

Adams,  Romance  of  Submarine  Engineering.     J.  B.  Lippincott  Company. 

Baldwin  and  Livengood,  Sailing  the  Seas.      American  Book  Company. 

Bishop,  Story  of  the  Submarine.     The  Century  Company. 

Bishop  and  Keller,  Industry  and  Trade.     Ginn  and  Company. 

Bond,  Pick,  Shovel,  and  Pluck.     Munn  and  Company. 

Cressey,  Discoveries  and  Inventions  of  the  Twentieth  Century.     E.  P.  Dutton. 

Collins,  The  Boys'  Book  of  Submarines.     F.  A.  Stokes  Company. 

Darling,  All  About  Ships.     Funk  and  Wagnalls. 

Domville-Fife,  Submarine  Engineering  of  Today.     J.  B.  Lippincott  Company. 

Hall,  Modern  Weapons  of  the  War,  By  Air,  Sea  and  Land.     Blakie. 

Hall,  Wonders  of  Transport.     Dodge  Publishing  Company. 

Hepburn,  Artificial  Waterways  of  the  World.     The  Macmillan  Company. 

Howden,  Boys'  Book  of  Steamships.     McClure  Company. 

Hughes,  Community  Civics.     Allyn  and  Bacon. 

Johnson,  Elements  of  Transportation.     D.  Appleton  and  Company. 

Johnson,  Panama  Canal  and  Commerce.     D.  Appleton  and  Company. 

Johnson,  Modern  Inventions.     F.  A.  Stokes  Company. 

Kennedy,  Newark  Study.     (For  teachers.)     Board  of  Education,  Newark,  N.  J. 

Maule,  Book  of  New  Inventions.     Grosset  and  Dunlap. 

Moffett,  Careers  of  Danger  and  Daring.     The  Century  Company. 

Smith,  The  Ocean  Carrier.     G.  P.  Putnam's  Sons. 

Smith  and  Jewett,  Introduction  to  the  Study  of  Science.     The  Macmillan  Company 

Talbot,  Lightships  and  Lighthouses.     J.  B.  Lippincott  Company. 

Talbot,  Submarines:   Their  Mechanism  and  Operation.     J.  B.  Lippincott  Company. 

Tappan,  Children's  Hour.     Vols.  14,  15.     Hough  ton  Mifflin  Company. 

Trafton,  Science  of  Home  and  Community.     The  Macmillan  Company. 


CHAPTER   XXI 
DEVELOPMENT   OF   LAND    TRANSPORTATION 

Problems.  —  i.    To  learn  how  development  in  transporta- 
tion has  changed  our  habits  and  customs. 

2.  To  learn  how  the  steam  engine  was  developed. 

3.  To  learn  how  the  steam  engine  works. 

4.  To  learn  how  the  locomotive  is  operated. 

5.  To  learn  the  value  of  electricity  in  transportation. 

6.  To  understand  the  types  and  value  of  bridges. 

Experiments.  —  i.   To  show  the  value  of  rails. 

2.  To  see  if  steam  can  do  work. 

3.  To  see  if  the  atmosphere  can  do  work. 

4.  Demonstration  of  steam  engine  model. 

Project  1.  —  A  STUDY  OF  LOCOMOTIVES. 

1.  Make  a  collection  of  pictures  of  locomotives.     Compare  for 
types. 

2.  Observe   locomotives.     Record    facts.     Observe   number    of 
drive    wheels  —  number    of    cylinders — size    of    wheels.     Engines 
used  for  what  type  of  work? 

3.  Observe  tender.    Its  use? 

4.  Compound  engine.     Principle? 

5.  How  is  the  engine  reversed? 

6.  Other  facts  and  explanations. 

Project  II.  —  To  MAKE  A  MODEL  STEAM  ENGINE. 
Project  III.  —  A  STUDY  OF  BRIDGES. 

1.  To  make  bridges,  illustrating  different  types  of  construction. 
Use  mechanical  construction  toys. 

2.  To  find  bridges  in  your  vicinity  of  the  different  types  —  girder, 
truss,  cantilever,  arch,  and  suspension. 

Early  travel  in  America.— The  earliest  settlers  in  America 

323 


324    DEVELOPMENT  OF  LAND   TRANSPORTATION 

had  no  way  of  travel  except  on  foot.  It  was  six  years  after 
Virginia  was  settled  before  the  first  horses,  only  nine  of 
them,  were  brought  from  Europe.  And  it  was  a  great  many 
years  later  before  roads  began  to  take  the  place  of  trails. 

Changes  in  transportation.  —  Two  generations  ago  a 
New  York  business  man  who  wished  to  go  to  Philadelphia 
had  the  choice  of  a  hazardous  boat  trip  or  a  tedious  two 

days'    journey     by 

OVERLAND  TO  THE  PACIFIC.          stage     coach.      To- 

day  he    travels    in 
comfort  in   a   little 
over      two      hours. 
The  San  Antonio  and  San  Diego  Mail-Line     jn      jg         Marcus 


Heading  an  advertising  circular  seventy  years  Whitman    took    five 

ago. 

months     to     travel 

across  the  continent.  To-day  New  York  and  San  Fran- 
cisco are  less  than  five  days  apart  by  train,  or  two  days 
by  airplane.  Our  trains  now  run  frequently  a  mile  a 
minute,  and  our  best  expresses  average  fifty  miles  an 
hour  including  stops,  while  airplanes  are  built  that  can 
travel  one  hundred  and  fifty  miles  an  hour. 

How  we  depend  on  transportation.  —  Our  customs  de- 
velop by  transportation.  Our  early  ancestors  who  lived 
in  America  had  much  more  varied  industries  than  we 
have  to-day.  Clothing,  food,  and  even  household  utensils 
were  made,  either  at  home  or  in  the  near  vicinity.  To- 
day all  is  changed.  We  have  become  specialists.  In 
farming,  one  man  raises  wheat,  another  corn,  and  another 
horses.  One  factory  makes  cotton  cloth,  another  woolen 
cloth,  and  in  the  mills  where  these  cloths  are  made,  each 
person  performs  a  single  piece  of  work  in  the  complicated 
process.  We  have  also,  owing  to  the  fact  that  transpor- 


THE   USE  OF  RAILS  IN  TRANSPORTATION       325 

tation  has  developed  so  greatly,  come  to  depend  on  other 
parts  of  the  world  for  our  various  needs.  For  example,  a 
boy  may  have  had  for  his  breakfast  grapefruit  from 
Florida,  or  an  orange  from  California,  corn  flakes  from 
Kansas  City,  with  milk  from  a  town  from  fifty  to  three 
hundred  miles  away.  The  wool  in  his  suit  came  from 
the  West;  the  silk  in  his  necktie  came  from  Japan, 
the  material  in  his  gloves  from  India,  the  leather  in  his 
shoes  from  South  America,  his  hat  from  Panama,  and 
he  studies  from  a  book  made  in  New  York,  and  reads  a 
magazine  from  Chicago.  The  World  War  has  brought 
forcibly  to  our  minds  the  importance  of  transportation  in 
movement  of  food,  fuel,  and  men,  for  it  was  by  means  of 
Paris  and  London  busses  that  some  of  the  critical  battles 
of  the  war  were  won. 

The  use  of  rails  in  transportation.  —  The  first  methods 
of  transportation  made  use  of  roads  with  stone  or  earth 


Comparison  of  loads  which  can  be  drawn  by  horses  on  dirt  roads  and  on  rails 

foundations,  but  in  1630,  wooden  rails  were  used,  as  it  was 
found  much  larger  loads  could  be  pulled  along  such  tracks. 
Iron  rails  were  first  used  in  1737  in  transporting  coal  in 
England.  In  about  1800,  a  flanged  iron  wheel  was  used 
in  connection  with  the  rails,  and  by  this,  more  work  could 
be  done,  for  ten  horses  could  draw  on  this  road  as  much  as 
four  hundred  horses  could  on  an  ordinary  street. 


326    DEVELOPMENT  OF  LAND  TRANSPORTATION 


Experiment.  —  To  show  the  value  of  rails. 
Materials:    A  toy  car  and  track.     Spring  balance.     A  tray  of   moist 

sand.     String. 
Method:  Load  the  car  heavily.     Connect  to  spring  balance  and  see  what 

force  is  necessary  to  draw  it  over  the  tracks.     What  force  is  required 

to  draw  it  over  the  moist  sand?  over  the  floor? 
Results  and  Conclusion:  Tabulate  the  results.     What  do  they  show ? 

The  first  use  of  steam.  —  So  far  as  we  know,  Hero  of 
Alexandria,  about  one  hundred  and  fifty  years  before 
Christ,  contrived  a  toy  in  which  steam  caused  a  ball  to  re- 
volve, but  it  was  a  great  many  centuries  before  steam 
was  actually  put  to  practical  use. 

Experiment.  —  To  see  if  steam  can  do  work. 

Materials:  Half-liter  flask,     i -hole  stopper.     Long  glass  tubing.     Beaker. 

Ring  stand. 

Method:  Fill  the  flask  \  full  of  water.    Make  a  wide  bend  near  the  middle 

of  a  3-foot  piece  of  glass  tubing. 
Pass  one  end  of  the  tube  through  the 
stopper  far  enough  so  that  when  in- 
serted in  the  flask  the  lower  end  is 
within  half  an  inch  of  the  bottom  of 
the  flask.  Place  a  beaker  under  the 
other  end  of  tube.  Heat  the  flask 
to  generate  steam.  Be  sure  the  stop- 
per is  tightly  inserted. 

Results:  Is  water  lifted  in  the  tube  ? 

Conclusion:  What  is  the  force  that  has 
lifted  the  water? 

Experiment.  —  To  see  if  the  atmosphere 

can  do  work. 

Materials:  The  same  materials  used  in 
the  experiment  above.  An  empty 
sirup  can.  Stopper  to  fit  the  open- 
ing. 

(i)  Method:  Boil  the  water  in  the  flask  and  allow  the  water  to  be  forced 
out  as  in  the  preceding  experiment.  Remove  the  flame.  Lift  the 
beaker  of  water  so  that  the  end  of  the  bent  tube  extends  into  the  water. 
Cool  the  flask  by  placing  a  wet  cloth  over  its  surface. 


THE   FIRST  USE  OF   STEAM 


327 


Result:  As  the  steam  condenses,  what  happens  ? 

Conclusion:  What  causes  the  water  to  do  this? 

(2)  Method:  Put  a  little  water  in  the  sirup  can.     Boil  it  until  the  air  is 

driven  out.     Close  the  can  so  tightly  that  no  air  can  enter  after  the 

steam  condenses.     Remove  the  flame  at  the  same  time  the  can  is  being 

closed. 
Result:  As  the  can  cools  and  the  steam  condenses  what  happens  to  the 

can? 
Conclusion:  Explain  the  observed  result. 

The  first  steam  engine  was  not  the  work  of  any  one 
man.  Denys  Papin,  a  Frenchman,  made  the  first  model 
of  a  steam  engine  with  a  piston,  the  idea  being  suggested 
to  him  by  an  experi- 
ment in  which  the 
atmosphere  would 
lift  a  \veight  if  a 
vacuum  were  created 
in  a  cylinder  under 
a  piston.  The  prin- 
ciple used  by  Papin 
was  developed  by 
Savary,  a  Cornish 
miner,  who  made  the 
first  useful  engine. 
In  1710,  Newcomen, 
who  was  an  English 
iron  worker,  com- 
pleted an  improved 
engine.  This  engine 
had  a  piston  which 
was  raised  by  steam  pressure.  The  steam  was  con- 
densed in  the  cylinder  C  by  a  jet  of  water  (see  figure),  thus 
reducing  the  pressure.  This  allowed  atmospheric  pressure 
at  A  to  push  the  piston  to  its  original  position.  Newcomen 


The  Newcomen  Engine.  When  valve  5  is  open, 
steam  from  B  pushes  the  piston  up;  when  5  is 
closed  and  W  is  open  a  jet  of  water  condenses  the 
steam  and  the  atmosphere  pushes  the  piston  down. 


328    DEVELOPMENT  OF  LAND  TRANSPORTATION 

used  the  first  engine  for  pumping  purposes  and  transmitted 
this  power  from  his  engines  to  the  pump  by  means  of  a  beam 
somewhat  like  the  walking  beam  of  our  old  steamboats. 

Watt's  engine.  —  Half  a  century  later  James  Watt 
was  asked  to  repair  a  model  of  the  Newcomen  engine  used 
for  demonstration  in  Glasgow  University  after  London 
mechanics  had  failed  to  make  it  work.  Watt  became 
greatly  interested,  and  as  a  result  of  his  study,  the  modern 
engine  with  its  slide  valve  and  piston  was  invented. 
Steam  generated  in  the  boiler  enters  the  steam  chest.  After 
entering  the  steam  chest,  the  steam  passes  alternately 
through  two  openings  into  the  ends  of  the  cylinder,  first 
on  one  side  and  then  on  the  other  of  the  piston.  The 
entrance  of  the  steam  into  the  cylinder  is  controlled  by 
the  slide  valve,  which  is  moved  by  an  eccentric  placed  on 
the  shaft  of  the  fly  wheel  of  the  engine.  Steam  entering 
at  one  end  of  the  cylinder  pushes  the  piston  in  one  direc- 
tion ;  and  when  entering  at  the  other  end  pushes  it  back 
again.  This  is  practically  the  principle  of  the  modern 
steam  engine. 

Experiment.  —  Demonstration  of  steam  engine  model. 

Materials:  Steam  engine  model. 

Method:  Turn  the  fly  wheel  until  the  slide  valve  is  in  position  to  admit 
steam  first  on  one  side  of  the  piston  head  and  then  on  the  other.  Make 
two  diagrams  of  the  cylinder  and  steam  chest  to  show  these  two  posi- 
tions of  the  piston  and  slide  valve.  Examine  the  eccentric  to  see  how 
it  works  and  explain  its  purpose. 

Watt's  improvements  were  these :  first,  he  kept  the 
cylinder  hot  all  the  time  instead  of  having  it  alternately 
heated  and  cooled;  second,  he  had  steam  pushing  the 
piston  on  both  of  its  strokes  instead  of  one  only;  third, 
be  regulated  the  flow  of  steam  to  the  cylinder  so  that 


THE  STEAM  ENGINE  OF  TODAY  329 

the  steam  from  the  boiler  was  cut  off  when  the  piston  had 
made  one-fourth  of  its  stroke,  which  more  than  doubled 
the  efficiency  of  the  engine,  the  added  work  coming  from  the 


GOVERNOR,  PEYOL.VEO 
MOW  GEAR/NO*  CUTOFF^.. .. 


A  steam  engine.    Study   the  working   parts.      Can  you  explain  how  the  governor 
cuts  off  the  supply  of  steam? 

expansion  of  the  steam  ;  fourth,  he  used  oil  for  lubrication  and 
to  keep  the  steam  from  escaping  around  the  working  parts. 
The  steam  engine  of  to-day.  —  The  steam  engine  in  use 
to-day,  although  having  some  improvements,  works  on 
the  same  principle  as  Watt's  engine.  Two  devices  give 
it  an  even  and  a  regular  motion.  These  are  the  fly  wheel 
and  the  governor.  The  fly  wheel,  by  its  momentum,  pre- 
vents a  slowing  up  of  the  engine  when  the  load  is  suddenly 
increased.  The  governor  automatically  regulates  the  supply 
of  steam  entering  the  steam  chest.  This  is  done  by  the 
centrifugal  action  of  the  balls  of  the  governor  (A  B  in 
diagram).  As  these  balls  rotate  faster  they  swing  outward 
and  partly  close  the  steam  valve.  This  causes  the  engine  to 
slow  up  a  little.  The  balls  revolve  less  rapidly,  and  more 
steam  is  allowed  to  come  in.  These  two  opposing  actions 
soon  become  adjusted  so  that  an  even  speed  is  maintained. 


330    DEVELOPMENT  OF  LAND   TRANSPORTATION 


The  locomotive  engine.  —  Wonderful  as  the  locomotive 
is,  if  one  understands  the  principle  of  Watt's  engine,  he 
can  apply  it  to  locomotives.  If  you  mount  an  engine,  a 
boiler,  and  a  furnace  on  wheels,  you  have  a  locomotive. 


Which  of  these  engines  is  for  speed  and  light  loads?     Which  for  heavy  loads  and  slow 
traffic?     How  do  you  know? 

You  will  notice  that  some  locomotives  have  larger  driv- 
ing wheels  than  others.  Freight  engines  which  draw 
heavier  loads  have  smaller  driving  wheels,  while  passenger 
engines  built  for  speed  have  larger  ones.  Can  you  see 
why  there  should  be  this  difference? 

A  detailed  study  of  a  locomotive  engine  should  be  made 
as  a  home  project.  If  you  use  the  diagram  which  is  given 
on  page  331,  and  study  about  the  operation  of  a  locomo- 
tive in  an  encyclopedia,  you  should  be  able  to  report  fully 
in  class  how  this  wonderful  device  works. 

The  replacing  of  steam  by  electricity.  —  In  many  parts 
of  the  country  electricity  is  taking  the  place  of  steam 
power  to  propel  locomotives.  Steam  locomotives  are  not 


REPLACING  STEAM  BY  ELECTRICITY 


331 


very  efficient  in  their  use  of  coal,  as  it  takes  a  large  amount 
of  coal  to  furnish  the  amount  of  power  necessary.  In  some 
parts  of  our  country,  coal  is  not  as  easily  obtained  as  is 


THPOTTLE  MLV£ 


Essential  parts  of  the  locomotive.    Locate  the  piston  and  boiler. 

water  power.  Water  power  can  be  harnessed  so  as  to  pro- 
duce electricity  by  means  of  great  dynamos,  consequently 
it  is  much  cheaper,  because  water  power  is  usually  abun- 
dant where  railroads  have 
to  go  up  heavy  grades. 
In  many  parts  of  the 
West,  railroad  systems 
have  been,  or  are  now 
being,  rapidly  furnished 
with  electric  power.  The 
Chicago,  Milwaukee,  and 
St.  Paul  Railway,  for 
example,  now  operates 
nearly  six  hundred  miles 
of  road  by  electricity, 

while  the  Pennsylvania,  the  New  York  Central,  the 
New  York,  New  Haven  and  Hartford  in  the  East  are 
gradually  electrifying  more  and  more  of  their  systems. 


Model  of  an  electric  locomotive  built  in  the 
U.  S.,  1888. 


332     DEVELOPMENT  OF  LAND   TRANSPORTATION 


A  modern  electric  locomotive. 

The  development  of  railways  in  the  United  States.  - 
The  first  locomotive  to  be  operated  in  America  was  the 
Stourbridge  Lion,  imported  from  England,  and  run  August 
8,  1829.  The  first  railroad  in  the  United  States  was 
built  from  the  granite  quarries  in  Quincy,  Massachusetts, 
to  the  coast  in  1826.  The  road  was  only  four  miles  long, 
and  the  cars  were  hauled  by  horses.  The  first  locomotive 
built  in  America  for  practical  service  was  called  the  "Best 
Friend."  The  first  railway  opened  to  the  public  was 
operated  in  Charleston,  South  Carolina,  and  the  train 
was  drawn  by  the  "  Best  Friend,"  which  was  not  con- 
sidered a  "  best  friend  "  by  all  the  passengers,  for  it  belched 
out  black  cinders  and  live  sparks,  setting  fire  to  their  um- 
brellas and  clothes.  But  with  all  these  discomforts, 
railroad  traveling  was  begun  in  this  country  with  a  sub- 
sequently enormous  development.  By  1835  eight  hun- 
dred miles  of  railroad  had  been  built  in  the  United  States. 


ELECTRIC  RAILWAYS  333 

By  1 86 1,  there  were  thirty  thousand  miles,  while  at  the 
present  time  there  are  probably  about  two  hundred  fifty 
thousand  miles  of  railway.  Railroad  systems  have  been 
brought  to  their  highest  degree  of  efficiency  in  America 
and  their  equipment  far  surpasses  that  of  all  other  coun- 
tries. It  is  estimated  that  there  are  probably  about  ninety 
thousand  locomotives,  sixty  thousand  passenger  cars, 
and  nearly  three  million  freight  cars  on  railways  in  the 
United  States  at  the  present  time.  We  all  know  the 


In  the  early  days  of  steam  railway  travel. 

efficiency  of  the  modern  railway  with  its  low  grades,  its 
automatic  block  signal  system  by  means  of  which  the  pass- 
ing of  trains  is  regulated,  and  the  improvements  in  road 
beds,  bridges,  and  rails.  The  war  has  shown  us  that  the 
American  engineer  and  the  American  railway  system 
were  very  efficient  in  France,  and  the  future  will  probably 
show  even  greater  improvements. 

Electric  railways.  —  Any  of  us  who  live  in  large  cities 
can  appreciate  better  than  others  what  the  "  electrics  " 
mean  to  hundreds  and  thousands  of  people  who  depend 
upon  them  for  their  daily  use,  when  we  see  a  tie-up  in 
the  street  railway  traffic  during  rush  hours.  Electric 
cars  have  to-day  become  necessities  in  every  large  com- 
munity. The  motorman  excites  our  admiration  as  we 
watch  him  move  the  lever  of  the  controller  and  see  the  car 
respond  so  quickly.  A  detailed  study  of  the  electric 


334  DEVELOPMENT  OF  LAND  TRANSPORTATION 


car  cannot  be  made  here,  but  any  one  who  will  take  the 
trouble  to  work  up  a  project  can  understand  a  great,  deal 
about  the  mysteries  of  the  action  of  the  electric  car  and  the 
growth  of  electric  lines  in  this  country.  In  1884  public 
electric  railways  were  in  operation  in  Providence,  Rhode 
Island,  and  in  Kansas  City.  In  1888  an  electric  road  with 


Trace  the  trolley  car  circuit  from  power  house  dynamo  to  trolley,  controller,  motor, 
through  car  wheels  to  rails  and  back  to  the  dynamo. 

twenty  cars  was  operated  in  Richmond,  Virginia.  When 
we  realize  that  to-day  thousands  of  towns  and  cities  are 
equipped  with  complete  electric  railway  systems,  and  that 
thousands  of  other  towns  are  connected  by  suburban  lines, 
we  can  realize  how  much  electricity  has  done  for  us  in 
these  recent  years. 

The  electric  car  circuit.  —  Electricity  from  the  dynamo 
in  the  power  station  is  conducted  to  the  trolley  wire.  It 
is  brought  through  the  trolley  to  the  electric  motors  be- 
neath the  car,  but  goes  through  a  number  of  controlled 


BRIDGES,  THEIR  PART  IN  TRANSPORTATION      335 

resistances.  The  motorman  by  moving  the  controller 
handle  determines  just  how  much  resistance  is  to  oppose 
the  electricity,  and  thus  he  regulates  the  amount  of  cur- 
rent which  passes  through  the  motor.  The  current  passes 
from  the  motor  through  the  wheels  of  the  car  to  the  rails 
and  is  conducted  by  the  rails  and  ground  back  to  the 
dynamo  in  the  power  house,  thus  completing  the  circuit, 
for  you  doubtless  remember  that  electricity  can  do  no 


+MAGNET 


North  magnetic  poles  are  marked  +-   and  south  poles  -  .      Try  to  explain  how  contin- 
uous motion  results  in  this  motor. 

work  unless  there  be  a  complete  circuit  from  its  source 
out  through  the  wires,  motors,  or  other  instruments,  and 
back  to  its  source  again. 

Bridges  and  their  part  in  transportation.  —  Only  in 
civilized  times  have  bridges  come  into  existence.  Primi- 
tive peoples  when  traveling  used  to  ford  the  stream,  or  if  it 
was  too  deep,  they  would  cross  by  boat.  The  Romans  were 
bridge  builders  of  the  stone  arch  type.  But  with  the  com- 


336  DEVELOPMENT  OF  LAND  TRANSPORTATION 


ing  of  steam  and  electric  railways,  bridges  came  to  have  a 
much  greater  significance.  Railways  which  must  hold 
to  a  nearly  even  level  frequently  used  a  bridge  to  keep  an 

even  grade,  and  it  is  often  found 
cheaper  to  throw  a  bridge  over  a 
valley  or  wide  stream  than  to  pay 
out  the  extra  money  in  grading  and 
laying  rails,  to  get  around  the 
obstacle. 

The  principles  on  which  bridges 
are  made.  —  A  very  simple  bridge 
is  seen  on  any  country  road. 
Logs,  or  perhaps  iron  beams,  are 
placed  across  the  brook,  the  ends 
resting  on  solid  piers.  This  is 
known  as  a  girder  bridge.  Such 
bridges  do  very  well  for  a  short 
span,  but  where  a  long  distance 
must  be  covered,  a  bridge  may  be 
built  so  as  to  hold  the  load  without 
using  such  heavy  beams.  A  study 
of  the  diagrams  shows  how  this 
is  done  by  means  of  what  is 
called  the  truss  bridge.  When 
still  greater  distances  have  to  be 
bridged,  such  as  in  the  case  of 
the  great  bridge  over  the  Saint 
Lawrence  River,  Quebec,  where 
the  principal  span  is  1800  feet 
long,  we  have  the  principle  of 
the  cantilever  used.  Other  types 
Types  of  bridges.  of  bridges  that  we  are  all  familiar 


PRINCIPLES  ON  WHICH  BRIDGES  ARE  MADE     337 

with  are  the  arch,  built  of  stone  or  steel,  and  the  suspen- 
sion type.  The  last  named  is  the  most  graceful  bridge  of 
all.  A  familiar  example  of  the  arch  is  the  new  Hellgate 
bridge  in  New  York,  while  one  of  the  most  beautiful 
suspension  bridges  in  the  world  is  the  old  Brooklyn 
bridge  spanning  the  East  River. 

REFERENCE  BOOKS 

Articles  on  Transportation.     The  American  City. 

Bishop  and  Keller,  Industry  and  Trade.     Ginn  and  Company. 

Chisholm,  Handbook  of  Commercial  Geography.     Longmans,  Green  and  Company. 

Corbin,  Mechanical  Inventions  of  Today.     Seeley,  Service  and  Company. 

Corbin,  The  Marvels  of  Scientific  Inventions.     Seeley,  Service  and  Company. 

Earle,  Home  Life  in  Colonial  Days.    The  Macmillan  Company. 

Forman,  Stories  of  Useful  Inventions.     The  Century  Company. 

Gregory-Keller-Bishop,  Physical  and  Commercial  Geography.     (For  teachers.)    Ginri 

and  Company. 

Hodgdon,  Elementary  General  Science.    Hinds,  Hayden  and  Eldredge. 
Holland,  Historic  Inventions.     Jacobs  and  Company. 
Howden,  Boys'  Book  of  Locomotives.     Grant,  Richards,  London. 
Moffett,  Careers  of  Danger  and  Daring.     The  Century  Company. 
Municipal  Year-book,  Transportation.    City  of  New  York. 
Page,  Roads,  Paths,  and  Bridges.     (For  teachers.)     Sturgis  and  Walton. 
Rocheleau,  Great  American  Industries,  Transportation.    Flanagan  and  Company 
Rowe,  Problems  of  City  Government.     (For  teachers.)     D.  Appleton  and  Company 
Smith  and  Jewett,  Introduction  to  the  Study  of  Science.    The  Macmillan  Company 
Warman,  The  Story  of  the  Railroad.    D.  Appleton  and  Company. 
Williams,  How  to  Make  Things.     Sully,  Kleinteich,  N.  Y. 
Wright,  Stories  of  American  Progress.    Charles  Scribner's  Sons. 


H.  W.  CIV.  SCI.  COMM. 22 


CHAPTER  XXII 
THE   AUTOMOBILE   AND    GAS   ENGINE 

Problems.  —  i .    To   learn   about   the   early   development 
of  the  gas  engine  and  automobile. 

2.  To  understand  how  power  comes  from  gas. 

3.  To  learn  how  the  four-cycle  engine  works. 

4.  To  understand  the  value  of  such  accessories  as  the 
carburetor. 

5.  To  learn  how  gasoline  is  fed  from  the  tank  into  the 
engine. 

6.  To  learn  how  kerosene  may  be  substituted  for  gasoline. 

7.  To  learn  about  the  uses  of  tractors. 

Experiments.  —  i.   To  show  explosive  and   non-explosive  mixtures  of 
gases. 

2.  To  explain  momentum. 

3.  To  illustrate  the  difference  between  the  "  jump  "  spark  and  the 
11  make-and-break  "  spark. 

Project  I.  —  To  BECOME  AN  EFFICIENT  AUTOMOBILE  CARETAKER. 

1 .  How  to  replace  a  tire  and  to  patch  an  inner  tube. 

2.  How  to  wash  and  dust  an  automobile. 

3.  Proper  care  of  the  oiling  system. 

4.  Proper  care  of  grease  cups  and  other  parts. 

5.  Proper  care  of  storage  battery. 

6.  How  to  diagnose  engine  trouble. 

7.  How  to  remove  carbon  from  the  engine. 

8.  How  to  clean  spark  plugs. 

9.  What  attention  must  be  given  to  the  cooling  system. 
10.   How  to  leave  the  car  for  the  winter  if  not  to  be  used. 
Project  II.  —  To  BECOME  AN  AUTOMOBILE  DRIVER. 

338 


THE  DEVELOPMENT  OF  THE  AUTOMOBILE        339 


Project  III.  —  To  UNDERSTAND  THE  TRANSMISSION  SYSTEM  OF  AN 

AUTOMOBILE. 

The  clutch,  the  gear  shift,  the  universal  joint,  the  differential. 
Project  IV.  —  To  MAKE  A  SIMPLE  STORAGE  BATTERY. 
Project  V.  —  To  MAKE  AN  ELECTROLYTIC  RECTIFIER. 

Early  development  of  the  gas  engine.  —  As  early  as  1680, 
Huyghens,  an  astronomer,  showed  that  an  engine  could 
be  driven  by  exploding  gun  powder  in  a  cylinder,  the  re- 
sulting pressure  being  used  against  a  piston.  A  hundred 
years  later,  an  Englishman,  Robert  Street,  suggested  that 
turpentine  might  be  used  in  place  of  gun  powder.  In  the 
early  part  of  the  nineteenth  century,  two  Frenchmen 
made  engines  which  used  gas  instead  of  steam,  but  none 
of  the  early  attempts 
were  put  into  prac- 
tical use,  the  first 
real  gas  engine  being 
devised  in  France  in 
1862.  This  gas  en- 
gine, called  an  inter- 
nal combustion  en- 
gine, was  the  fore- 
runner of  the  modern 
automobile  engine. 

The   development 

of  the  automobile.  —  It  seems  hardly  possible  that  the 
first  motor  cycle  was  not  made  until  1886,  and  it  was  almost 
ten  years  later  before  automobiles  began  to  be  seen  on 
the  streets.  The  first  automobile  race  in  this  country 
was  held  in  1895  in  Chicago,  and  there  were  only  two 
contestants,  one  of  which  broke  down  and  the  winner 
could  only  make  seven  miles  an  hour.  Twenty  years 


An  English  horseless  carriage  in  1833.    Operated  by 
steam. 


340  THE  AUTOMOBILE  AND   GAS  ENGINE 


KI 


Hit' 


The  automobile  monopolizes  our  streets  to-day.  Typical  street  traffic  in  the  city  of 
New  York  in  1836,  1886,  and  1921.  Notice  also  that  three  periods  of  lighting  are 
shown  by  the  street  lamps,  oil,  gas,  and  electric.  Telephone  poles  are  shown  in  the 
1886  picture.  Why  not  in  the  other  two  ? 


HOW  WE  GET  POWER  FROM  GAS 


341 


ago  there  were  not  more  than  one  hundred  automobiles  in 
the  United  States :  to-day  there  are  over  7,000,000  motor 
vehicles  of  different  kinds  registered.  A  speed  of  over 
two  hundred  miles  an  hour  has  been  attained  in  racing, 
and  in  some  parts  of  the  country  motor  trucks  are  taking 
the  place  of  railroad  trains  for  rapid  transportation  of 
freight. 

How  we  get  power  from  gas.  —  The  fuel  for  the  internal 
combustion  engine,  whether  liquid  or -gas  in  its  natural 
state,  must  be  in  the  form  of  a  gas  when  it  enters  the  engine 
cylinder.  Gasoline,  kerosene,  and  alcohol  are  three  liquids 
which  may  be  vaporized  easily,  and  therefore  are  suitable 
fuels  for  the  gas  engine.  Alcohol  is  too  expensive,  how- 
ever, for  common  use.  Kerosene  finds  limited  use  in 
slow  speed  engines.  Gasoline  vaporizes  readily  and  is  the 
fuel  most  commonly  used.  When  the  vapor  is  mixed 
with  the  right  amount  of  air  and  lighted  it  explodes.  When 
the  gas  explodes  it  generates  heat.  This  heat  expands 
the  gases  in  the  cyl- 
inder of  the  engine, 
drives  the  piston, 
and  thus  gives 
power. 

Experiment.  —  To  show 
what  gas  mixtures 
are  explosives. 

Materials:   Test    tubes. 

Illuminating  gas.     i- 

pound  coffee  can  with 

a  hole  \  inch  in  diameter  in  the  cover  and  another  similar  hole  in  the 

side  of  the  can  i  inch  from  the  bottom.    Test  tubes.     Rubber  bands. 
Method:   A.  Measure  off  on  5  test  tubes  lengths  from  the  closed  end  to 

represent  5%,  10%,  15%,  20%,  25%,  of  the  total  length,  respectively. 

Mark  these  positions  with  rubber  bands  about  the  tubes.     Fill  tubes 


fill 


Burning 
6 


342 


THE  AUTOMOBILE  AND   GAS  ENGINE 


with  water.  Let  illuminating  gas  enter  tubes  to  fill  them  respectively 
with  5%,  10%,  15%,  20%,  and  25%  of  gas.  Then  take  each  in  turn, 
let  the  water  run  out  and  air  enter.  Close  the  tube,  invert  and  shake 
to  mix  the  air  and  gas  thoroughly.  Bring  a  lighted  match  to  the  mouth 
of  the  tube,  to  test  for  an  explosive  mixture. 

B.  Put  the  cover  tightly  on  the  can.  If  the  cover  fits  loosely  tighten 
it  with  paper.  Fill  completely  with  illuminating  gas.  Apply  a  flame 
to  the  hole  in  the  cover  and  allow  the  gas  to  burn  as  long  as  it  will. 
Note  all  changes  in  the  flame.  As  the  gas  burns  what  is  entering  the 
can  through  the  hole  on  the  side? 
Results  and  Conclusion:  What  are  the  results  in  A  ?  in  B  ? 

What  can  you  say  in  regard  to  "  explosive  limits  of  gas-air  mixtures  "  ? 

Explain  changes  in  the  flame  and  the  final  result  observed  in  B. 

An  explosive  mixture.  —  Experiments  with  mixtures 
of  illuminating  gas  and  air  show  that  the  proportion  in 
which  the  two  are  mixed  is  very  important  in  producing  an 
explosive  mixture.  Not  all  mixtures  will  explode.  The 
range  of  explosive  mixture  of  illuminating  gas  and  air  is 
from  93%  air  and  7%  gas  to  80%  air  and  20%  gas.  If 
five  parts  illuminating  gas  are  mixed  with  ninety-five 
parts  air  and  a  lighted  match  is  brought  to  the  mixture, 

nothing  will  happen,  but 
if  a  flame  is  introduced  into 
a  mixture  of  air  and  gas 
which  is  15%  gas  there  will 
be  a  violent  explosion.  A 
mixture  with  over  20%  gas 
will  burn  quietly  where  ex- 
posed to  more  air. 

Home  experiment  with  gasoline. 
—  Make  a  quarter-inch  hole  about 
halfway  up  the  side  of  a  pint  tin 
coffee  pot.  Warm  the  bottom  of 
the  pot  until  just  too  hot  to  hold 
in  the  hand.  Put  ten  drops  of  gas- 
oline into  the  pot.  Close  the  cover. 


Bent 
Wire> 


THE  FOUR-CYCLE  GASOLINE  ENGINE 


343 


GASOLINE 
TANK 


INTAKE  MANIFOLD 

X^- 

/CASOLINE  VAPOP 
JV        AND  AIR 


Bring  a  flame  to  the  opening  on  the  side  of  the  pot.  When  the  right 
mixture  of  air  and  gasoline  vapor  is  secured  the  ignition  of  the  explosive 
charge  will  throw  the  cover  open  violently  and  give  a  good  illustration 
of  the  power  derived  from  exploding  gases.  Illuminating  gas  may  be  used 
in  place  of  gasoline. 

The  carburetor.  —  All  automatic  engines  have  a  de- 
vice called  tjie  carburetor  in  which  a  liquid  fuel  is  vaporized 
and  mixed  with  air,  making  it  ready  to  enter  the  engine. 
If  gasoline  is  sprayed  into  the  air,  no  liquid  will  be  seen. 
It  immediately  vaporizes  and  mxies  with  the  air.  The 
oxygen  of  the  air  is  needed  in  burning  the  gasoline,  and  in 
the  right  proportion 
an  explosive  charge 
is  produced.  If  too 
much  gasoline  be 
present  or  if  too 
much  air  be  present, 
the  mixture  will  not  H  FLOAT 

explode.  The  car- 
buretor requires 
rather  delicate  ad- 
justment in  order  to 

produce  a  proper  explosive  charge.  The  explosive  charge 
passes  from  the  mixing  chamber  or  intake  manifold  of  the 
carburetor  through  an  inlet  valve  into  the  engine  cylinder 
at  the  proper  time. 

The  four-cycle  gasoline  engine.  —  Two  forms  of  engines 
are  found  in  use.  These  are  two-cycle  and  four-cycle  en- 
gines. The  two-cycle  has  one  power  stroke  for  each  revo- 
lution of  the  fly  wheel.  Each  revolution  of  the  fly  wheel 
involves  two  strokes  of  the  piston,  hence  there  is  but  one 
power  stroke  in  two  strokes  of  the  piston.  The  four-cycle 
engine  is  the  simpler  of  the  two  and  is  the  one  in  common 


CASOLINE  ADJUST/NO. 
SCREW 


The  carburetor. 


344 


THE  AUTOMOBILE   AND   GAS   ENGINE 


use.  The  operation  of  the  four-cycle  engine  will  be  ex- 
plained below  by  describing  what  happens  in  each  of  the  four 
strokes.  A  careful  study  of  the  diagrams  showing  four  differ- 
ent strokes  will  help  us  to  understand  how  this  engine  works. 
The  suction  stroke  or  charging  stroke.  —  Let  us  start 
with  the  piston  in  the  cylinder  (see  A)  just  starting  to 
move  out.  As  the  crank  revolves 
through  half  a  circle  the  piston  will 
move  downward.  During  this  stroke 
valve  7  is  open  but  valve  0  remains 
closed.  A  mixture  of  air  and  gasoline 
vapor,  sometimes  called  "  the  charge," 
is  brought  into  the  cylinder  from  the 
mixing  chamber  of  the  carburetor  by 
"  suction."  Is  it  pulled  or  pushed  in? 
At  the  end  of  this  stroke  valve  /  closes 
and  we  have  the  condition  shown  in 
(B),  the  cylinder  being  filled  with  an 
explosive  charge  of  air  and  gasoline. 

The  compression  stroke.  —  During  the  next  half  revo- 
lution of  the  crank,  the  piston  is  moving 
into  the  cylinder.  Both  valves  /  and 
0  are  closed.  The  charge  is  compressed 
into  the  clearance  space  above  the  dotted 
line.  As  the  volume  of  the  gas  decreases 
its  pressure  rises.  Its  temperature  also 
increases.  The  pressure  at  the  end  of  the 
compression  stroke  may  be  as  high  as 
100  to  200  pounds  per  square  inch  and 
its  temperature  300°  to  700°  F. 

The  expansion  stroke  or  power  stroke. 
—  When  the  gas  is  under  this  high  pres-     B.  compression  stroke. 


A .  Suction  stroke. 


USE  OF  FLY  WHEEL 


345 


OUTLET 


C.  Power  stroke. 


sure  and  the  piston  is  just  ready  to  start  outward  again, 

an  electric  spark  ignites  the  charge.     The  fuel  now  ex- 
plodes and  great  heat  results.     The  temperature  is  raised 

to   over  3000°  F.     The  heat  tends  to 

cause   expansion,  but   in  the   confined 

space  effects  tremendous  pressure.    This 

pressure,  amounting  to  300  to  700  pounds 

per  square  inch,  is  exerted  during  the 

entire  stroke.     This  is  often  called  the 

power  stroke  because  it  is  the  only  stroke 

which  receives  power  from  the  fuel. 
Exhaust  stroke.  —  At  the  end  of  the 

expansion  stroke  the  cylinder  is  full  of 

burned  gases.    As  the  piston  starts  back 

valve  O  opens,  allowing  the  burned  gases 

to  be  forced  out.     At  the  end  of  this 

stroke  valve  O  closes  while  I  opens,  and  the  engine  is 
ready  to  begin  the  suction  stroke  again. 
Use  of  flywheel.  —  Since  force  is  ex- 
erted upon  the  piston  during  but  one  of 
its  four  strokes,  we  would  have  very 
jerky  motion  were  it  not  possible  to 
carry  some  of  this  energy  over  to  the 
other  strokes.  The  force  is  communi- 
cated to  a  heavy  fly  wheel  which  is  set 
in  motion.  The  momentum  thus  given 
to  the  fly  wheel  makes  it  a  storehouse 
of  energy  for  the  other  three  strokes. 

D.  Exhaust  stroke.         Experiment.  —  To  explain  momentum . 

Materials:  A  small  heavy  cart.  A  3-foot  board. 
A  light  wheel  (may  be  wood  or  cardboard)  arranged  to  revolve  on  an 
axle.  A  heavy  wheel  (may  be  lead  or  iron)  arranged  to  revolve  on  an 


346 


THE  AUTOMOBILE  AND   GAS  ENGINE 


Method:    (i)  Support  the  board  to  make  an  angle  of  30°  with  the  table. 
Place  the  car  first  at  B  and  then  at  C,  and  release  it.     Note  how  far 

it  runs  on  the  table  in 
each  case  before  it  stops. 
(2)  Take  hold  of  the 
light  wheel  and  give  it 
a     whirl.      Note    how 
many  seconds  it  contin- 
ues   to    turn.     Repeat 
with  the  heavy  wheel. 
Results  and     Conclusions: 
Compare  results  in  (i) 
and  explain  reason  for  the  difference. 
Compare  results  in  (2)  and  explain  reason  for  the  difference. 
Application:  How  is  this  principle  made  use  of  in  engines? 

Cooling  the  cylinder.  —  Much  of  the  heat  resulting 
from  compression  and  from  combustion  of  the  charge  is 
absorbed  by  the  cylinders.  Unless  this  heat  can  be  taken 
away  as  fast  as  it  is  received  and  the  cylinders  kept  at  some 
temperature  below  that  at  which  the  gas  will  burn,  there 
will  be  a  premature  explosion  or  "  back  firing."  Suppose 
the  charge  were  ignited  by  a  hot  cylinder  just  before  the 
end  of  the  compression  stroke.  What  would  be  the  re- 
sult? 

Air-cooled  engines.  —  There  are  two  systems  of  cooling, 
—  by  air  and  by  water.  The  amount  of  heat  given  off 
by  a  hot  body  increases  with  the  area  of  radiating  sur- 
face. By  making  gas  engine  cylinders  with  flanges  or  by 
studding  the  surface  with  metal  projections,  the  amount 
of  heat  conducted  to  the  air  and  radiated  is  increased. 
By  bringing  in  colder  air  and  driving  the  warmed  air  away 
faster  than  it  would  circulate  in  natural  circulation,  cool- 
ing is  hastened.  This  is  done  in  air-cooled  automobiles 
by  means  of  a  fan. 


HOW  THE   CHARGE   IS   IGNITED 


347 


Water-cooled  engines.  —  When  water  is  used  for  cool- 
ing, a  water  jacket  surrounds  the  explosion  chamber  of  the 
engine.  Through  this,  water  is  kept  in  circulation  some- 
times by  gravity,  but  better 
by  means  of  a  pump  driven 
by  the  engine.  In  the  auto- 
mobile the  hot  water  leaving 
the  water  jacket  is  carried 
through  a  radiator  where  it 
is  cooled  rapidly.  A  fan 
helps  circulate  the  air  around  A,BC  D-  CYUNDEPS^PUMP 

the  passages  Of   the  radiator.     Water-cooling  system  of  an   automobile 

By  this  means  a  relatively 

small  amount  of  water  is  sufficient  to  keep  the  engine  cool. 
How  the  charge  is  ignited.  —  In  practically  all  gas  en- 
gines to-day  an  electric  spark  sets  off  the  charge  in  the 
cylinder.  There  are  two  systems  of  ignition :  the  "  jump- 
spark  "  and  the  "  make-and-break." 

Experiment.  —  To  see  the  difference  in  method  of  producing  the  "  jump  " 

spark  and  the  "  make-and-break  "  spark. 
Materials:   A  spark  coil.     An  induction  coil.     A  spark  plug.     A  key  or 

switch. 

Method  and  Results:  (i)  Connect  poles  of  secondary  coil  of  the  induction 
coil  to  the  spark  plug.  Send  a  momentary  current  from  2  dry  cells 
into  the  primary  coil  of  the  induction  coil.  This  shows  the  "  jump  " 
spark. 

(2)  Connect  2  dry  cells  in  series  with  a  spark  coil,  leaving  a  gap  in 
the  circuit.  Bring  the  two  wires  at  this  gap  as  close  together  as  pos- 
sible without  touching.  Is  there  any  spark?  Touch  the  two  wires 
and  break  the  circuit  instantly.  Is  there  any  spark?  This  results 
from  a  "  self-induced  "  current.  Can  you  find  out  what  this  means? 
Application:  Can  you  see  any  advantage  in  the  "  jump  "  spark  for  auto- 
mobile use? 


The  jump  spark  is  used  in  high  speed  engines  such  as  are 


348 


THE  AUTOMOBILE  AND   GAS  ENGINE 


found  in  the  automobile  and  airplanes.  The  spark  jumps 
the  gap  between  the  wires  at  the  end  of  the  spark  plug 
which  is  screwed  on  to  one  end  of  the  engine  cylinder. 
The  make-and-break  spark  is  used  in  low  speed  engines 
such  as  are  found  on  motor  boats. 

How  the  spark  is  produced.  —  An  electric  spark  can 
be  produced  only  by  a  high  voltage  current.  Both  dry 
cells  and  storage  batteries  give  a  low  voltage  current. 
It  is  possible  to  "  step  up  "  a  low  voltage 
to  a  high  voltage  by  means  of  a  spark  coil. 
It  will  make  an  interesting  project  for 
some  of  you  to  find  out  how  the  induction 
coil  changes  a  low  to  a  high,  voltage  for 
the  jump  spark  use ;  also  to  learn  how  a 
single  coil  such  as  is  used  for  gas  lamp- 
lighters and  for  the  make-and-break 
spark  changes  the  voltage.  In  some 
cases  a  magneto  is  used.  This  produces  a  high  voltage  cur- 
rent and  it  replaces  both  batteries  and  coils. 


A  spark  plug. 


£0c  a 
Automobile  transmission  systems. 


Transmission.  —  Before  an  automobile  can  move,  the 
power  developed  in  the  engine  must  be  transmitted  to  the 
wheels.  This  is  usually  done  by  what  is  called  the  "  shaft 
drive"  but  sometimes,  particularly  in  trucks,  by  the 


THE   MUFFLER 


349 


"  chain  drive"  The  differences  in  methods  employed 
in  the  two  types  are  shown  in  the  illustration.  The  fly 
wheel  of  the  engine  (C  in  figure)  is  the  outside  or  driving 
member  of  the  clutch.  This  revolves  when  the  engine 
is  running.  When  the  clutch  spring  (E)  is  released,  the 
inner  member  of  the  clutch  is  pushed  into  C  so  tightly  that 
both  C  and  D  revolve  together.  A  shaft  from  D  passes 
into  the  transmission  case  F,  where  by  various  gears,  dif- 
ferent powers  or  speeds  may  be  applied  to  the  propeller 
shaft  which  runs  from  the  transmission  case  to  the  rear  axle. 
Here  the  power  is 
given  to  the  driving 
wheel.  If  a  "  chain 
drive "  is  used  the 
propeller  shaft  (/) 
and  differential  (K) 
will  be  replaced  by 
the  chain,  axle,  and  ^ 
differential  indicated  \ 
by  O,  N,  P  in  the 
diagram.  Many 
automobiles  use  a 
multiple  drive  clutch 
instead  of  a  cone  clutch  shown  in  the  figure  referred  to 
above.  This  type  of  clutch  is  shown  in  the  accompany- 
ing figure.  Attached  to  the  inside  of  the  fly  wheel  (B) 
are  a  number  of  driving  disks ;  alternating  with  these  are 
driven  disks  which  communicate  the  power  by  means  of  the 
shaft  F  to  the  transmission  gears.  Can  you  explain  why  pres- 
sure on  the  clutch  pedal  (K)  allows  the  engine  to  run  free  ? 
The  muffler.  —  As  the  burned  gas  leaves  the  engine 
cylinder,  it  is  at  a  pressure  much  above  that  of  the  atmos- 


The  multiple  drive  or  disk  clutch. 


350 


THE  AUTOMOBILE  AND   GAS  ENGINE 


phere.  If  allowed  to  discharge  directly  into  the  air  at 
this  high  pressure  it  gives  a  very  loud  and  objectionable 
explosive  sound.  The  muffler  is  a  device  to  reduce  the 
noise.  By  leading  the  gases  from  the  engine  into  a  series 
of  chambers,  each  one  larger  than  the  one  previously 
occupied  by  the  gas,  the  gas  expands  gradually  and  finally 
escapes  at  a  pressure  but  little  above  that  of  the  atmos- 
phere. 

Engines  of  many  cylinders.  —  A  single  large  cylinder 
used  with  a  heavy  fly  wheel  will  do  satisfactory  work  for 
many  purposes.  For  automobiles,  however,  it  is  desirable 
to  have  at  least  four  cylinders.  The  four  piston  rods  all 
turn  the  same  main  shaft.  But  the  explosions  occur  at 
different  times,  so  that  during  each  one  of  the  four  strokes 
of  the  piston  there  will  be  a  power  stroke  in  one  of 

the  cylinders.  By  this  means 
each  explosion  is  smaller  and  a 
lighter  fly  wheel  may  be  used  to 
give  a  steady  motion.  Auto- 
mobile engines  are  built  with  four, 
six,  eight,  and  twelve  cylinders. 
The  power  may  or  may  not  in- 
crease with  the  number  of  cylin- 
ders, but  the  greater  evenness 
obtained  from  the  twelve  cylin- 
der engine  is  of  but  little  advan- 
tage over  that  obtained  from  the  six  cylinders,  since  there 
are  so  many  more  parts  to  move. 

Use  of  kerosene  in  gas  engines.  —  The  rapid  increase 
in  gasoline  engines  has  resulted  in  a  greatly  increased 
consumption  of  gasoline.  This  has  caused  the  price  of 
gasoline  to  double  in  the  last  few  years.  Kerosene  is  now 


AVESMC 


^e 


£/QHT  CYJ-/NDEPS 


Showing  the  greater  evenness  of 
power  distribution  as  the  number 
of  cylinders  is  increased. 


TRACTORS  AND  THEIR  USES 


351 


cheaper  than  gasoline  and  with  suitable  device  for  chang- 
ing it  to  gas  it  gives  satisfactory  results  in  low  speed  en- 
gines. Kerosene  has  a  higher  fuel  value  than  gasoline, 
but  it  does  not  burn  so  rapidly  and  is  not  therefore  so  well 
adapted  to  high  speeds.  A  kerosene  engine  is  usually 
started  on  gasoline  and  when  the  engine  gets  warmed  up, 
a  turn  of  a  lever  shifts  over  to  the  kerosene  fuel.  Kero- 
sene is  being  used  successfully  in  stationary  engines  and 
tractors. 

An  age  of  automobiles.  —  Thanks  to  the  low-priced  and 
excellent  engines  now  on  the  market,  a  person  need  not 
be  wealthy  to  own  a  motor  cycle  or  a  motor  car.  Mil- 
lions of  pleasure  cars  are  now  operated,  while  commercial 
cars  and  especially  motor  trucks  have  come  into  much 
greater  use  since  the  World  War.  A  period  of  activity 
in  the  construction  of  good  roads  is  favorable  to  the  in- 
creased use  of  automobiles. 

Tractors  and  their  uses.  —  In  late  years  the  gas  engine 


The  caterpillar  tractor  is  useful  in  peace  and  in  war. 

has  come  into  prominence  on  the  farm,  where  it  does  better 
and  more  economically  the  work  of  cultivation,  reaping, 
binding,  and  thrashing,  formerly  done  by  horses.  Most 


352  THE  AUTOMOBILE  AND   GAS  ENGINE 

large  farms  now  use  the  gasoline  engine  in  many  ways. 
The  war,  too,  made  use  of  tractors,  not  only  in  dragging 
heavy  guns  and  supplies,  but  also  in  that  interesting  de- 
velopment of  modern  warfare  known  as  the  tank.  The 
tank  or  so-called  caterpillar  tractor  became  an  important 
weapon  of  offense  not  only  to  go  over  the  roughest  kind  of 
ground,  but  also  to  tear  up  barbed  wire  entanglements 
and  even  to  go  through  heavy  embankments  and  walls  of 
masonry. 

REFERENCE  BOOKS 

Baker,  Boys'  Book  of  Inventions.    Doubleday,  Page  and  Company. 

Burns,  The  Story  of  Great  Inventions.     Harper  Brothers. 

Collins,  Keeping  Up  with  Your  Motor  Car.     D.  Appleton  and  Company. 

Cressey,  Discoveries  and  Inventions  of  the  Twentieth  Century.  E.  P.  Dutton  Com- 
pany. 

Darrow,  The  Boys1  Own  Book  of  Great  Inventions.    The  Macmillan  Company. 

Doubleday,  Stories  of  Inventors.     Doubleday,  Page  and  Company. 

Dyke,  Motor  Manual.     (For  teachers.)     A.  L.  Dyke,  St.  Louis. 

Hodgdon,  Elementary  General  Science.     Hinds,  Hayden  and  Eldredge. 

Maule,  Boys'  Book  of  New  Inventions.     Grosset  and  Dunlap. 

Page,  The  Modern  Gasoline  Automobile.     Henley  and  Company. 

Rolt- Wheeler,  The  Wonders  of  the  War  on  Land.  Lothrop,  Lee  and  Shepard  Com- 
pany. 

Smith  and  Jewett,  Introduction  to  the  Study  of  Science.     The  Macmillan  Company. 

Trafton,  Science  of  Home  and  Community.    The  Macmillan  Company. 


CHAPTER  XXni 
TRANSPORTATION    THROUGH   AIR 

Problems.  —  i.  To  learn  of  the  development  of  aerial 
flight. 

2.  To  understand  the  principles  underlying  balloon  as- 
cension. 

3.  To  learn  the  advantages  of  airships  over  the  balloon. 

4.  To  understand  the  principle  by  which  heavier-than-air 
machines  can  remain  in  the  air. 

5.  To  learn  something  of  the  stability  and  method  of  con- 
trol of  airplanes. 

Experiments. —  i.  To  discover  what  common  gases  are  lighter  than 
air. 

2.  To  study  action  of  soap  bubble  balloons. 

3.  To  show  the  principle  of  the  glider. 

Project  I.  —  To  MAKE  AN  AIR  CRAFT  SCRAP  BOOK. 

Collect  pictures  showing  various  types  of  air  craft  —  machines 
and  aviators  who  are  of  interest  in  history  or  who  have  made  flight 
records.  Also  show  different  advantages  of  air  craft.  News  clippings 
about  important  air  craft  events. 

Project  II.  —  To  MAKE  A  FIRE  BALLOON. 

Project  III.  —  To  MAKE  A  BOX  KITE. 

Project  IV.  —  To  MAKE  A  MODEL  AIRPLANE. 

Through  the  air.  —  To  fly  as  on  the  wings  of  a  bird  has 

become  an  actuality  at  last.     While  air  transportation  was 

slowly  coming  into  its  own,  the  World  War  suddenly  threw 

it  into  prominence,  and  as  successful  warfare  depended 

H.  w.  civ.  sci.  COMM.  —  23        353 


354 


TRANSPORTATION  THROUGH  AIR 


largely  on  the  knowledge  of  the  movements  of  the  enemy, 
so  the  airplanes,  dirigibles,  and  balloons  became  the  eyes 
of  the  army,  and  went  a  long  way  toward  winning  the  war 
for  the  ollies.  Man  has  produced  machines  in  which  he 
can  fly  as  well  as  birds,  and  can  also  perform  trick  move- 
ments which  birds  do  not  even  attempt.  Transportation 
through  the  air,  the  dream  of  centuries,  has  now  become  a 
reality.  There  are  two  classes  of  machines  now  in  use 
in  the  service,  known  as  lighter- than-air  machines  and 
heavier-than-air  machines.  Their  names  indicate  exactly 
what  they  are. 

Earlier  lighter-than-air  machines.  —  The  French  were 
the  pioneers  in  developing  balloons.     The  earliest  balloons 

were  made  by  the  Montgol- 
fier  brothers  in  1783,  and 
were  called  fire  balloons, 
because  a  straw  fire  was 
built  under  the  gas  bag  to 
supply  hot  air  which  caused 
them  to  rise.  In  that  same 
year,  hydrogen,  which,  as 
you  know,  is  a  gas  many 
times  lighter  than  air,  was 
used.  In  the  next  fifty 
years  numerous  ascents  were 
made  by  adventurous  spirits, 
and  so  knowledge  of  the 
envelope  of  air  surrounding 
the  earth  was  very  greatly 
enlarged.  Some  daring  balloonists  reached  an  altitude  of 
seven  miles  above  the  earth,  and  although  they  nearly  lost 
their  lives  in  this  hazardous  flight  they  found  that  there 


One  of  Montgolfier  brothers'  fire  balloons. 


WHY  BALLOONS  RISE  AND  FLOAT  355 

was  only  one-fourth  as  much  air  there  as  there  was  at 
sea  level,  so  we  have  been  able  to  estimate  pretty  clearly 
that  if  this  ratio  were  kept  up,  there  would  be  little  if 
any  air  left  one  hundred  miles  above  the  surface  of  the 
earth.  Indeed,  at  a  height  of  twenty- three  miles,  which 
has  been  reached  by  some  exploring  balloons  sent  up 
with  weather  instruments  in  them,  it  has  been  found  that 
only  one  three-hundredths  of  the  air  was  left  above  the 
balloon. 

Why  balloons  rise  and  float.  —  A  balloon  rises  because 
it  is  pushed  up  by  air  which  is  denser  than  the  gas  in  the 
balloon.  Since  only  those  gases  which  are  lighter  than  air 
can  be  used  in  balloons,  it  may  interest  you  to  find  out 
experimentally  some  of  the  common  gases  which  are  suit- 
able for  balloons. 

The  higher  one  goes  in  the  atmosphere,  the  rarer  it 
becomes  and  the  less  lifting  power,  because  its  density 
decreases  as  one  ascends.  When  a  balloon  has  risen  until 
its  total  weight  just  equals  the  air  it  displaces,  it  ceases  to 
rise,  and  becomes  a  floating  body,  very  much  as  we  have 
seen  in  the  case  of  boats.  A  balloon  from  which  ballast  is 
dropped  will  rise,  while  if  gas  is  allowed  to  escape,  the 
balloon  will  sink  to  a  lower  level.  Why? 

Experiment.  —  To  discover  what  common  gases  are  lighter  than  air. 

Materials:  Collect  two  test  tubes  each  of  carbon  dioxide,  oxygen,  hydro- 
gen, and  illuminating  gas. 

Method:  Hold  one  tube  of  each  gas  mouth  down  for  3  minutes  and  apply 
test  for  the  presence  of  the  gas.  Hold  another  tube  of  each  gas  mouth 
up  for  3  minutes  and  apply  test  for  the  presence  of  the  gas.  Which 
gases  are  lighter? 

Method  of  Collecting  Gases:  i.  Carbon  dioxide.  Put  marble  or  washing 
soda  in  the  generator  (A);  add  dilute  hydrochloric  acid.  Close  and 
collect  gas  by  water  displacement. 


356  TRANSPORTATION   THROUGH  AIR 

2.  Oxygen.     Drop  a  small  lump  of  oxone  into  water  in  the  generator 

3.  Hydrogen.     Put  zinc  into  dilute  sulphuric  acid  in  generator. 

4.  Illuminating  gas.     Connect  rubber  tube  to  gas  cock  and  collect 
as  in  other  cases  over  water. 

Buoyancy  of  air  holds  up  objects  in  the  sea  of  air  just  as 
water  holds  up  objects  which  weigh  less  than  the  amount 
of  water  displaced.  One  thousand  cubic  feet  of  air  weigh 
eighty  pounds,  and  one  thousand  cubic  feet  of  hydrogen 
weigh  only  five  and  one-half  pounds.  A  balloon  carrying 
200,000  cubic  feet  of  hydrogen  will  then  have  a  lifting 
power  of  74^  times  200  or  14,900  pounds.  Part  of  this 
lifting  power  would  be  used  to  hold  up  the  material  of  the 
bag  and  balloon  car,  and  the  rest  would  be  used  for  ballast 
and  passengers. 

Experiment.  —  To  study  action  of  soap  bubble  balloons. 

Make  a  thick  soap  solution  with  which  you  can  blow  large  bubbles. 
Attach  a  glass  tube  with  smooth  fire  polished  edge  by  means  of  a  rubber 
tube  to  the  gas  jet.  By  pressure  on  the  rubber  tube  the  flow  of  gas  may 
be  regulated. 

Blow  bubbles  with  the  gas.  Shake  off.  Observe:  (i)  Some  rise 
directly.  Explain  why.  (2)  Others  sink  at  first,  and  then  rise. 
Watch  these  carefully.  Try  to  discover  the  cause  of  this  action.  How 
does  this  illustrate  the  practice  of  throwing  out  ballast? 

Uses  of  balloons.  —  Balloons,  as  we  have  already  seen, 
would  not  be  of  much  value  for  transportation,  as  one 
would  have  to  depend  entirely  upon  the  wind  currents.  A 
skilled  balloonist  is  able  by  shifting  the  altitude  of  his  bal- 
loon to  take  advantage  of  winds  moving  in  different  direc- 
tions. We  have  seen  their  use  in  scientific  experiments. 
The  captive  balloon  at  the  front  lines  of  the  armies  in  the 
World  War  proved  of  very  great  value  indeed,  as  they 
were  enabled  to  direct  the  fire  of  artillery,  prevented  sur- 
prise movements  of  troops,  and  gave  signals  in  case  of  at- 


THE  DIRIGIBLE 


357 


tack  of  hostile  airplanes.  These  balloons  were  held  to 
earth  by  a  long  cable  attached  to  a  windlass,  which  al- 
lowed them  to  go  to  the  height  of  two  or  three  thousand 
feet.  In  case  of  attack 
by  enemy  airplanes,  they 
were  drawn  down 
quickly,  thus  preventing 
the  loss  of  many  bal- 
loons on  each  side. 

The  dirigible.  —  For  a 
great  many  years  people 
worked  on  some  plan  to 
steer  balloons.  In  1850 
a  Frenchman  by  the  name 
of  Giffard  built  a  cigar- 
shaped  gas  bag  under 
which  he  placed  a  car 
containing  a  steam  en- 
gine. This  was  not  very 
successful,  but  later  gaso- 
line engines  were  used. 
Captain  Renard  of  the 
French  army  in  1885  was 
the  first  man  to  bring  his  cigar-shaped  balloon  back  to  its 
starting  point.  Santos  Dumont  in  1901  won  a  $20,000 
prize  for  steering  his  dirigible  around  Eiffel  Tower  and 
coming  back  to  his  starting  point,  a  distance  of  three  or 
four  miles.  It  is  interesting  to  remember  that  he  used  an 
automobile  engine,  so  that  the  automobile  helped  in  the 
development  of  the  dirigible.  The  first  part  of  the  war 
brought  into  great  prominence  the  rigid  dirigibles  of  Count 
Zeppelin  of  Germany.  These  great  machines  were  made 


An  army  observation  balloon. 


358 


TRANSPORTATION  THROUGH  AIR 


of  a  large  number  of  sections,  each  of  which  was  a  distinct 
balloon  by  itself,  and  the  entire  lifting  body  of  the  balloon 
was  made  rigid  by  means  of  aluminum  bars  and  rings, 
so  that  it  looked  like  a  great  silver  cigar  as  it  moved  through 
the  air.  Although  some  of  these  airships  were  over  500 
feet  in  length,  and  could  lift  a  load  of  many  tons,  yet  they 
did  not  do  the  damage  they  were  expected  to  do.  They 
made  many  long  trips  without  stops,  frequently  pene- 
trating the  countries  of  the  allies,  but  were  soon  found  to  be 
at  the  mercy  of  the  faster  airplanes.  In  these  times,  how- 
ever, the  commercial  possibilities  of  airships  seem  to"  be 


i^ •— ^^— — •— — — 

The  English  dirigible  which  made  the  first  round  trip  across  the  Atlantic,  landing 
Long  Island,  N.  Y. 

very  great.  The  English  dirigible,  R  34,  in  July,  1919, 
made  the  first  round  trip  between  Europe  and  America, 
the  return  trip,  with  favoring  winds,  taking  only  a  little 
over  seventy- two  hours. 

Forerunners  of  the  airplane.  —  Every  boy  knows  how 
to  fly  a  kite.  He  also  knows  that  the  stronger  the  wind, 
the  better  his  kite  will  fly.  When  a  wind  blows  against 


THE  INVENTION  OF  THE  AIRPLANE 


359 


the  surface  at  right  angles  it  exerts  a  pressure  which  tends 
to  push  the  surface  in  the  direction  of  the  wind.  When  a 
wind  blows  against  the  surface  at  some  other  angle,  it  tends 
to  move  the  body  at  an  angle  to  the  wind  direction.  We 
all  know  how  wind  striking  at  an  angle  against  the  pin 
wheel  causes  it  to  revolve  rapidly,  while  it  causes  the  kite 
to  rise  to  a  higher  level.  This  is  due  to  the  fact  that  the 
wind  upon  striking  the  kite  is  deflected,  but  reacts  to  push 
the  kite  in  a  direction  which  depends  upon  the  angle  between 
the  kite  and  wind  direction.  From  the  box  kite,  which 
has  been  used  for  a  great  many  years  in  England  to  raise 
observers  above  the  ground,  to  the  glider  is  only  a  step. 
The  glider  is  only  a  huge  box  kite  arranged  to  hold  an 
operator. 

Experiment.  —  To  show  the  principle  of  the  glider:  Fold  a  piece  of  stiff 
paper  7  inches  square  in  the  middle  in  order  to  cut  the  two  sides  of  the 
glider  just  alike.  Cut 
out  the  glider  in  the 
form  suggested  in  the 
diagram  which  is  ap- 
proximately to  scale. 


Slip  a  metal  clip  over 
the  front  edge  at  the 
center  to  give  greater 
stability.  With  a 
little  practice  you  can 
make  this  travel 
across  the  room.  Remember  that  in  starting  the  glider  you  give  it  a 


thrust  forward,  pointing  it  slightly  upward, 
you  can  explain  why  it  stays  up  so  long. 


Make  a  diagram  by  which 


The  invention  of  the  airplane. — Like  so  many  other  great 
inventions,  the  airplane  is  not  the  work  of  any  one  man, 
although  Americans  have  had  a  prominent  place  in  its  de- 
velopment. Professor  Langley  succeeded  in  making  a 


360 


TRANSPORTATION   THROUGH   AIR 


model  airplane  run  by  a  small  steam  engine  fly  out  over 
the  Potomac  for  900  yards  at  the  rate  of  about  25  miles 
an  hour.  The  Wright  brothers  experimented  with  gliders, 
and  learned  much  about  the  laws  of  flight.  In  1903  they 
were  able  to  place  a  gasoline  engine  on  their  glider,  and 
made  exhibition  flights  of  a  whole  minute  in  duration. 
Think  of  the  rapidity  with  which  improvements  have  been 
made,  for  to-day  non-stop  flights  of  over  twenty-four 

hours  are  taken,  hydro- 
plane and  airplane  have 
successfully  flown  across 
the  Atlantic,  and  an  air- 
plane trip  half  around  the 
world,  from  England  to 
Australia,  was  success- 
fully made  in  1920  by  Sir 
Ross  Smith. 

The  first  transatlantic 
flight.  -  -  The  N-C  4 
(Navy-Curtiss  No.  4)  has 
the  distinction  of  being 
the  first  airplane  to 
cross  the  Atlantic.  On  May  31,  1919,  it  completed 
this  flight  of  4513  miles,  making  five  stops  on  the  way. 
The  longest  flight  on  the  trip  was  1380  miles  from  New- 
foundland to  the  Azores.  The  airplane  with  load  weighed 
14  tons.  The  commander  was  Lieutenant  Commander 
Albert  Gushing  Reed  of  the  United  States  Navy.  The 
trip  was  begun  at  Rockaway,  Long  Island,  and  ended  at 
Plymouth,  England.  The  first  non-stop  flight  was  made 
June  14,  1919,  from  Newfoundland  to  Ireland,  a  distance 
of  1890  miles,  by  the  Vickers-Vimy  airplane  piloted  by 


This  American  airplane,  the  N-C  4,  was  the  first 
to  cross  the  Atlantic. 


WHAT  SUPPORTS  THE  AIRPLANE  361 

Captain  John  Alcock  of  the  British  Army,  and  navigated 
by  Lieutenant  Arthur  W.  Brown,  an  American  in  the 
British  service. 


The  Vickers-Vimy  airplane  made  the  first  non-stop  flight  across  the  Atlantic. 

Types  of  airplanes.  —  In  the  growth  of  the  modern  air- 
plane we  have  had  two  types,  the  monoplane,  in  which  a 
single  set  of  planes  is  used,  and  the  biplane,  which  has 
come  into  almost  universal  favor.  The  fuselage,  or  body 
of  the  plane,  contains  the  motor,  room  for  pilot  and  operator 
as  well  as  storage  for  such  instruments  or  implements  as 
may  be  necessary.  At  the  rear  end  the  fuselage  tapers 
down  into  a  tail,  to  which  are  attached  the  rudders,  ele- 
vators, etc.  The  propellers  may  be  placed  in  front,  in  which 
case  we  call  the  plane  a  tractor,  while  if  the  propeller  is 
in  the  rear  it  is  called  a  pusher.  Numerous  models  have 
been  developed  on  these  two  lines.  The  hydroplane  is  an 
airplane  fitted  with  floats  on  which  it  will  rest  on  the 
water.  It  can  rise  from  the  water  and  alight  on  the  water. 

What  supports  the  airplane.  —  The  "  planes  "  of  the 
airplanes  are  not  really  planes  but  are  arched  or  convex 
as  viewed  from  the  top.  In  ordinary  flight  these  planes 
are  tilted  about  eight  degrees  from  horizontal,  and  as  the 
propeller  pushes  back  the  air  the  planes  are  pushed  for- 
ward. Because  of  this  motion  air  strikes  against  the 


362 


TRANSPORTATION  THROUGH  AIR 


concave  side  of  the  plane  with  considerable  force.     One 
result  of  this  is  the  lifting  effect  which  counterbalances 


Showing  general  features  of  the  tractor  airplane. 

the  effect  of  gravity,  which  is  always  pulling  downward 
on  the  machine. 


LIFTING  FORCE,  SPEED,  AND  POWER 


363 


The  support  of  the  airplane  is  somewhat  similar  to  that 
of  the  man  who  crosses  the  river  on  floating  logs  or  on 
loose  blocks  of  ice.  One  block  of  ice,  of  the  size  usually 
cut  in  ice  harvesting,  would  sink  if  the  man  were  to  stand 
on  it,  but  he  may  step  on  it,  and  before  it  has  time  to  sink, 
step  to  another  block,  and  then  still  another.  In  this  way 
he  can  travel  any  distance  on  blocks  of  ice  which  indi- 
vidually are  too 
small  to  support  his 
weight.  He  makes 
use  of  the  "  inertia 
of  rest."  It  takes 
time  to  set  the  block 
of  ice  into  motion 
and  before  it  sinks 
he  has  passed  on  to 
another  block. 

Can  you  think  of 

the    air    being    COm-     Why  the  airplane   does   not  fall  (see  text).     A  more 
scientific  explanation   involves   resolution  of  forces 

DOSed    Of    blocks    Of          as  suggested  by  diagram  at  right.     A  at  right  angles 
to  the  plane  is  one  component  of  the  air  force  act- 
air  ?      The     airplane         ing  upon  the  plane.    B  is  that  component   of  A 
which  lifts  the  plane. 

rests  on  one  block  of 

air  for  an  instant,  but  before  that  air  can  sink,  it  passes  on 
to  the  next  block,  and  so  on.  The  airplane  must  travel 
faster  in  air  than  the  man  on  ice  blocks,  because  air  can 
be  moved  faster  than  ice,  and  because  the  airplane  is 
heavier  than  the  man. 

Lifting  force,  speed,  and  power.  —  The  air  support 
depends  upon  the  area  of  the  plane.  Double  the  plane 
area  will  give  double  the  supporting  force.  The  air  sup- 
port also  depends  upon  the  speed ;  double  the  speed  will 
give  four  times  the  lifting  force.  It  is  thus  seen  that  the 


364  TRANSPORTATION  THROUGH  AIR 

lifting  power  of  an  airplane  increases  directly  as  the  sur- 
face area  of  the  plane  and  directly  as  the  square  of  the 
speed.  In  order  to  double  the  speed  of  an  airplane  the 
power  must  be  increased  eight  times. 

How  to  rise  and  fall.  —  By  driving  at  a  high  speed, 
the  planes  being  slightly  inclined,  the  air  exerts  an  upward 
pressure  sufficient  to  lift  the  airplane  to  a  higher  level.  At 
a  slower  speed  the  airplane  will  fall.  For  ordinary  flight, 
however,  special  "  elevator  "  planes  are  used  for  rising  and 
falling.  These  planes  may  be  tilted  at  will,  causing  an  up- 
ward or  downward  movement.  The  "  elevator  "  planes 
may  be  placed  in  front,  at  the  sides,  or  in  the  rear. 

Stability  of  airplanes.  —  Boats  in  water  are  often  sub- 
jected to  disturbance,  such  as  rocking  from  side  to  side 
and  pitching  bow  and  stern.  Airplanes  experience  this 
same  trouble,  but  in  greater  degree.  The  water  tends 
to  keep  a  boat  on  even  keel  to  a  greater  extent  than  the 
air  can  hold  an  airplane.  Gravity  is  pulling  the  machine 
down,  the  pressure  of  the  air  is  pushing  it  up.  The  pilot's 
seat  is  directly  over  the  center  of  gravity  of  the  airplane. 
If  the  center  of  upward  pressure  is  not  at  the  same  place 
as  the  center  of  gravity,  a  turning -effect  will  result.  The 
greater  the  distance  between  these  two  centers,  the  greater 
will  be  the  tendency  to  upset.  When  one  is  rising  or  fall- 
ing or  when  the  speed  is  being  changed,  the  center  of  pres- 
sure will  change.  The  pilot  can  change  the  center  of  pres- 
sure by  use  of  the  elevator  planes  and  he  tries  to  keep  the 
two  centers  in  the  same  position.  There  are  automatic 
devices,  too,  which  assist  him,  but  none  as  yet  can  re- 
place the  alertness  of  the  pilot,  who  must  acquire  the 
habit  of  instinctively  doing  the  right  thing  at  the  right 
time. 


PRESENT  AND   FUTURE 


365 


Present  and  future.  —  The  airplane  is  a  prime  necessity 
of  modern  warfare.  Scout  planes  are  built  which  can 
travel  one  hundred  and  fifty  miles  per  hour.  Regular  air- 
plane service  is  now  established  for  mail  delivery  between 
distant  cities  in  the  United  States.  Passenger  planes 
can  carry  fifty  passengers.  The  airplane  can  travel  for 
hours  without  a  stop  and  can  fly  in  any  wind  except  a  gale. 


Air  travel.     Passengers  getting  aboard. 

Transportation  in  air  may  'never  compete  to  any  great 
extent  with  land  and  water  transportation,  but  its  use- 
fulness has  already  been  established.  Boat  traffic  is  often 
seriously  interrupted  between  the  mainland  and  islands 
off  the  coast  in  the  winter.  Ice  packs  are  no  hindrances 
to  air  service.  We  may  confidently  expect  the  establish- 
ment of  an  air  line  between  America  and  Europe,  and  be- 
tween Europe  and  Asia,  since  the  feats  of  American 
and  British  fliers  have  proved  such  service  entirely  feasi- 
ble. 


366  TRANSPORTATION  THROUGH  AIR 

Scientific  study  of  conditions  in  the  upper  air  has  been 
made  possible  by  the  balloon  and  airplane,  the  balloon  with 
passengers  having  reached  an  altitude  of  30,000  feet,  while 
on  September  28,  1921,  Lieutenant  Macready  of  the  United 
States  Army  ascended  in  an  airplane  to  a  height  of  40,000 
feet  at  Dayton,  Ohio. 

The  development  of  the  airship  has  been  hindered  by 
numerous  disasters.  If  helium  can  be  obtained  in  quantity 
at  a  reasonable  cost  to  replace  the  inflammable  hydrogen 
now  used,  there  is  no  reason  why  the  airship  may  not  be- 
come an  important  agent  for  passenger  and  freight  service. 

REFERENCE  BOOKS 

Aero  chart;  Navigating  the  Air.    Doubleday,  Page  and  Company. 

Abbott,  Aircraft  and  Submarines.     G.  P.  Putnam's  Sons. 

Bachman,  Great  Inventors  and  their  Inventions.  American  Book  Company. 

Burns,  The  Story  of  Great  Inventions.     Harper  and  Brothers. 

Collins,  How  to  Fly.    D.  Appleton  and  Company. 

Collins,  The  Boys'  Book  of  Model  Aeroplanes.    The  Century  Company. 

Collins,  The  Air  Man,  His  Conquests  in  Peace  and  War.     The  Century  Company. 

Cressey,  Discoveries  and  Inventions  of  the  Twentieth  Century.  E.  P.  Button  Com- 
pany. 

Darrow,  The  Boy's  Own  Book  of  Great  Inventions.    The  Macmillan  Company. 

Dillacombe,  Boys'  Book  of  Airships.  (Interesting  because  of  story  of  early  de- 
velopment.) F.  A.  Stokes  Company. 

Johnson,  Flying  and  Some  of  Its  Mysteries.    Hodder  and  Stoughton. 

Johnson,  Modern  Inventions.    F.  A.  Stokes  Company. 

Maule,  Boys'  Book  of  New  Inventions.     Grosset  and  Dunlap. 

Moffett,  Careers  of  Danger  and  Daring.    The  Century  Company. 

Rolt- Wheeler,  The  Wonders  of  War  in  the  Air.  Lothrop,  Lee  and  Shepard  Com- 
pany. 

Smith  and  Jewett,  Introduction  to  the  Study  of  Science.    The  Macmillan  Company 

Towle,  Heroes  and  Martyrs  of  Invention.    Lothrop,  Lee  and  Shepard  Company. 

Trafton,  Science  of  Home  and  Community.    The  Macmillan  Company. 


CHAPTER   XXIV 

MEANS   OF   COMMUNICATION 

Problems.  —  i.    To   see   how   means   of  communication 
have  developed. 

2.  To  understand  different  methods  of  signaling. 

3.  To  appreciate  the  value  of  mail  service. 

4.  To    understand    how    communication   is    possible    by 
telegraph. 

5.  To  understand  the  working  of  the  telephone. 

6.  To  realize  what  an  important   part   newspapers  and 
other  printed  matter  play  in  the  world  to-day. 

Experiments.  —  i.  To  see  how  the  electric  telegraph  works. 

2.  To  study  the  action  of  the  telephone  receiver. 

3.  To  study  the  action  of  the  telephone  transmitter. 

4.  To  demonstrate  the  principle  of  wireless  telegraphy. 

Project    I.  —  To  BECOME  EXPERT  IN  "WIGWAG"  SIGNALING. 
Project  II.  —  To  LEARN  THE  SIGNIFICANCE  or  RAILROAD  SIGNALS 

AND  HOW  THEY  ARE  OPERATED. 

Project  III.  —  To  INSTALL  A  TELEGRAPH  LINE  BETWEEN  TWO 
HOUSES. 

Project  IV.  —  To  SET  UP  A  WIRELESS  AND  LEARN  TO  USE  THE 

INTERNATIONAL  CODE. 

When  we  were  babies  our  means  of  communication  were 
very  limited.  A  baby  can  cry  and  make  some  of  his 
wants  known,  largely  by  signs  and  facial  expression. 
Language  must  have  been  in  existence  for  a  great  many 

367 


368  MEANS  OF  COMMUNICATION 

centuries,  for  all  people  seem  to  have  this  means  of  com- 
munication. 

How  we  make  sounds.  —  Perhaps  you  know  how  diffi- 
cult it  is  for  a  young  child  to  learn  to  talk ;  you  have  seen 
little  children  struggle  with  the  formation  of  new  words. 
We  make  sounds  by  means  of  the  use  of  the  voice  box  or 
larynx.  This  is  located  in  the  region  we  call  the  "  Adam's 
apple."  It  is  at  the  upper  end  of  a  tube  which  leads  down- 
ward into  the  lungs.  This  voice  box  is  made  of  cartilage 
and  contains  two  cords  of  elastic  tissue,  the  weal  cords. 
These  cords  are  held  in  place  by  muscles  so  that  when  air 
is  forced  through  the  tube  the  cords  vibrate.  Stretching  or 
loosening  these  cords,  their  vibration  rates  are  changed  and 
hence  different  tones  are  produced.  By  means  of  forming 
the  lips  or  the  walls  of  the  mouth  in  different  positions  and 
causing  these  vocal  cords  to  vibrate  speech  is  made  possi- 
ble. Of  course  it  takes  much  practice  to  control  this  deli- 
cate organ,  hence  the  slow  learning  to  talk  on  the  part  of 
little  children. 

Early  communication  by  means  of  signals.  —  Signs 
and  signals  have  been  in  use  perhaps  as  long  as  words, 
and  they  find  as  important  place  in  the  world  to-day  as 
they  did  in  the  world  of  our  ancestors.  In  communicating 
by  signals  two  of  our  senses  are  made  use  of,  hearing  and 
seeing.  From  earliest  recorded  time  people  have  had  means 
of  signaling,  the  simplest  being  the  flaming  torch  or  bon- 
fire by  night.  The  Romans  maintained  fires  on  the  coast 
headlands  to  guide  their  triremes  of  war  and  commerce. 
The  Greeks  developed  an  elaborate  method  of  torch  signal 
communication.  By  using  a  screen  to  hide  the  torches 
not  in  use,  they  could  signal  all  the  letters  of  the  Greek 
alphabet  (see  figure).  The  American  Indians  sent  day- 


THE  USE  OF  LIGHT  IN  SIGNALING 


Torch  signals  used  by  the  Greeks. 


light  messages  by  covering  the  fire  for  a  short  time  with  a 
blanket  and  quickly  uncovering  it,  thus  rings  of  smoke 
were  sent  up  which  could  be  seen  20  miles  away.  The 
Eskimo  finds  it  more  difficult  to  use  fire  and  does  his  sig- 
naling with  his  arms. 
He  stands,  when 
possible,  on  a  hill 
against  the  sky  fac- 
ing his  observer. 
By  moving  his  arms 
up  and  down  at  the 
sides  he  gives  his 
message.  The  Es- 
kimo seems  to  have 
been  the  forerunner 
of  the  semaphore 

now  so  common  in  the  railroad  train  signaling  as  well  as  in 
the  navy  and  army  signaling. 

The  use  of  light  in  signaling.  —  Beacon  Hill  in  Boston 
derived  its  name  from  the  fact  that  a  beacon  light  there 
warned  the  colonists  of  the  approach  of  hostile  Indians. 
Lantern  light  gave  Paul  Revere  the  information  that 
started  him  on  his  famous  midnight  ride.  In  1870  the 
first  plan  to  use  flags  and  lanterns  to  transmit  messages 
by  a  practical  code  was  evolved.  This  was  soon  improved 
so  that  hundreds  of  different  messages  were  possible.  This 
led  to  the  wigwag  system  of  the  United  States  army. 
Our  lighthouses  with  numbered  flashes  tell  the  mariner  his 
location.  Rockets,  from  the  flaming  arrow  of  the  Indian 
to  the  brilliant  colored  rockets  used  in  the  World  War,  have 
been  a  common  and  important  means  of  signaling.  What 
boy  or  girl  does  not  know  the  use  of  a  small  mirror  in 

H.  W.  CIV.  SCI.  COMM. 24 


370 


MEANS  OF   COMMUNICATION 


throwing  a  beam  of  sunlight.     Heliograph  messages  are 
usually  limited  to  100  miles,  but  in  exceptional  cases  have 
been  sent  nearly  200  miles.     The  heliograph  is  an  impor- 
tant instrument  in  the 
national    forests,    being 
used  for  communication 
from  one  station  to  an- 
other. 

Ear  signals.  —  Signal- 
ing by  sound  requires  a 
medium,  usually  air,  to 
conduct  the  waves  from 
their  source  to  the  ear. 
You  may  remember 
that  sounds  are  vibra- 
tions of  matter  within 
such  limits  of  frequency 
(sixteen  to  forty  thou- 
sand a  second)  as  will 
affect  the  organ  of  hear- 
ing. When  a  sound 
wave  enters  the  passage  of  the  external  ear  it  beats  upon 
the  drum  membrane,  which  is  stretched  between  the 
outer  and  middle  ear.  In  the  middle  ear,  three  small 
bones  transfer  the  sound  energy  to  the  inner  ear,  which 
contains  a  fluid  and  thousands  of  tiny  fibers  of  varying 
length.  These  fibers  are  sensitive  to  particular  sounds 
and  transmit  the  sensations  to  the  nerve  which  carries 
them  on  to  the  brain. 

Ear  signals  are  perhaps  less  important  than  eye  sig- 
nals, and  yet  they  serve  many  conditions  where  eye 
signals  would  fail.  Crude  drums  and  trumpets  have 


Sending  a  message  by  heliograph. 


MAIL  SERVICE  371 

been  used  by  many  tribes  for  signaling,  and  it  is  said  that 
a  huge  megaphone  was  used  in  the  army  of  Alexander 
the  Great.  The  fog  horn,  automobile  horn,  and  fire  alarm 
are  examples  of  the  useful- 
ness of  ear  signals.  The 
door  bell,  telephone  bell, 
church,  and  school  bells,  and 
the  factory  whistle  all  give 
their  message  to  the  ear. 
But  all  methods  of  distance 
communication  devised  in 

.         .  Army  megaphone  of  Alexander  the  Great. 

thousands  of  years  by  man, 

are  clumsy  and  inefficient  indeed  when  compared  with 
the  telegraph,  cable,  telephone,  and  the  wireless,  which 
have  all  been  developed  within  the  memory  of  your 
parents  or  grandparents. 

Speaking  tubes.  —  Speaking  tubes,  once  quite  common 
in  apartment  houses,  schools,  and  commercial  buildings, 
are  now  almost  entirely  replaced  by  telephone  equip- 
ment. Speaking  tubes  are  metal  tubes,  between  one  and 
two  inches  in  diameter,  which  confine  the  sound  waves, 
forcing  the  vibrations  to  move  in  one  long  path  rather  than 
allowing  them  to  spread  out  and  lose  strength  as  they  do 
in  an  unconfined  air  space. 

Mail  service.  —  An  invaluable  service  to  commerce, 
business,  and  household  is  performed  by  the  mail  delivery. 
Even  the  distant  rural  population  receives  and  sends 
written  messages  at  small  cost  and  at  frequent  intervals 
of  time.  United  States  mail  carriers  have  the  right  of  way 
over  all  other  traffic,  except  in  emergencies  such  as  fire 
or  hospital  services.  To  increase  the  speed  of  delivery, 
air  service  has  already  been  established  between  some 


372 


MEANS  OF   COMMUNICATION 


large  cities,  and  in  the  future  this  will  undoubtedly  form 
an  important  branch  of  the  mail  service. 

How  letters  are  delivered  to  their  destination.  —  An 
interesting  project  would  be  for  some  member  of  the  class 
to  work  out  just  how  a  letter  gets  from  one  place  to  an- 
other. Its  method  of  travel  would  certainly  be  interest- 
ing. After  mail  is 
collected  from  the 
letter  box  it  is  taken 
to  the  post  office, 
where  it  is  roughly 
sorted  and  put  on  a 
mail  car  going  north, 
east,  south,  or  west. 
On  this  car  are  postal 
clerks  whose  busi- 
ness it  is  to  sort  out 
the  letters  going  to 
certain  cities  or  areas 
of  distribution.  Be- 
fore the  mail  train 
reaches  the  destina- 
tion of  your  letter, 
it  has  been  re-sorted 
with  all  the  other  first-class  mail  for  that  locality  and 
placed  in  another  bag,  to  be  put  off  at  the  proper  station. 
From  that  point  it  is  taken  to  the  post  office  and  is  either 
put  into  its  proper  box  or  sent  out  by  the  city  carrier  or 
the  rural  free  delivery  carrier  to  be  finally  delivered  to  the 
person  to  whom  it  is  addressed. 

The  telegraph.  —  As  early  as  1831,  Joseph  Henry,  who 
was  a  pioneer  in  work  with  electromagnets,    was  able  to 


Interior  of  a  mail  car. 


THE  TELEGRAPH 


373 


produce  sounds  at  a  distance  by  means  of  electromagnets. 
The  system  devised  by  Samuel  F.  B.  Morse  in  1832  and 
perfected  in  1843  is  the  one,  however,  which  has  been 
generally  used,  and  is  known  to-day  as  the  electric  tele- 
graph. Much  ex- 
perimental work  and 
many  improvements 
were  made  before  the 
telegraph  became 
commercially  pos- 
sible, but  on  the 
24th  day  of  May, 
1844,  the  first  mes- 
sage ever  sent  over 
a  commercial  tele- 
graph was  sent  from 
Washington  to  Bal- 
timore. The  mes- 
sage was  in  the  code 
of  "dots  and 
dashes,"  but  when 
transcribed  into  let- 
ters and  words  read 
"What  hath  God 
wrought'"  When 
we  compare  the 
state  of  affairs  in 
1844  with  the  con- 
ditions to-day  and 
realize  that  almost 
every  hamlet,  no  matter  how  remote,  is  connected  by  tele- 
graph with  its  neighbors,  and  that  almost  250,000  miles  of 


Morse's  first  telegraph  instrument.  When  M  is 
moved  under  O  each  contact  of  projecting  points 
lifts  P  and  lowers  J K  into  mercury  cups,  thus  clos- 
ing an  electric  circuit.  An  electromagnet  (h)  acts 
upon  a  pendulum  (F)  which  holds  a  pencil  (g)  in 
contact  with  a  strip  of  paper  which  is  constantly 
being  drawn  across  the  drum  (B)  by  clock  work. 
Each  time  the  circuit  is  closed,  the  electromagnet 
pulls  the  pendulum,  to  which  a  soft  iron  armature  is 
attached,  and  a  mark  is  drawn  across  the  strip  of 
paper. 


374  MEANS  OF  COMMUNICATION 

telegraph  lines  exist  in  this  country  we  can  see  what  an  im- 
portant place  it  has  in  our  lives.  It  is  estimated  that  there 
are  about  200,000,000  telegrams  sent  every  year,  or  prac- 
tically two  for  every  man,  woman,  and  child  in  the  United 
States. 

The  Atlantic  cable.  —  In  1857  a  submarine  cable  was 
laid  from  Newfoundland  to  Ireland,  but  after  working  for 
1 8  days  it  went  out  of  commission  and  it  was  not  until 
after  the  close  of  the  Civil  War  that  Cyrus  W.  Field  finally 
succeeded  in  laying  another  cable.  Since  that  tune  cables 
have  been  simplified  so  that  they  now  connect  almost  all 
parts  of  the  world. 

How  the  telegraph  works.  —  The  essentials  of  a  short 


SOUNDER, 


A  complete  telegraph  system.    Shown  ready  for  the  operator  at  the  station  at  the  left  to 
send  a  message. 

telegraph  line  for  connecting  the  houses  of  two  boys 
are  wire,  a  battery,  a  key,  and  a  sounder.  The  double 
wire  line  well  insulated  is  best,  but  a  one  wire  line  may  be 
used  if  connected  to  a  water  pipe  which,  with  the  ground, 
makes  a  return  circuit  to  replace  the  second  wire.  The 
battery  should  consist  of  two  or  more  gravity  cells  joined 
in  series.  The  key  is  a  device  for  opening  and  closing  the 
circuit.  The  interruption  in  the  flow  of  the  current  pro- 
duces a  signal  in  the  sounder  at  the  other  end  of  the  line. 


HOW  THE  MESSAGE  IS  RECEIVED 


375 


When  no  message  is  being  sent,  the  switch  attached  to  the 
key  is  closed.  The  current  always  flows  through  the 
entire  circuit  except  for  the  interruption  during  the  send- 
ing of  the  message. 

Experiment.  —  To  see  how  the  electric  telegraph  works. 

Materials:  Telegraph  sounder.     Key.     Two  gravity  cells.     Wire. 

Method:  Connect  a  key  and  sounder  in  circuit  with  two  gravity  cells 
joined  in  series.  Trace  the  wires  through  the  instrument.  Learn  the 
names  of  the  different  parts.  Open  the  switch ;  close  it  again ;  open 
the  switch  again  and  cbse  and  open  the  key.  Hold  it  closed  for  a  short 
and  for  a  long  period  of  time. 

Results:  Explain  the  results  obtained  in  each  of  these  trials.  Learn  to 
make  dots  and  dashes. 

When  through  with  the  apparatus  leave  with  circuit  closed.     How 
can  you  do  this? 

How  the  message  is  received.  —  The  sounder  con- 
sists of  an  electromagnet.  An  armature  is  attached  to  a 
strip  of  brass  pivoted 
at  one  end.  The  free 
end  of  the  strip  of  brass 
may  be  moved  up  and 
down  within  a  yoke 
against  which  it  strikes 
to  make  the  sound. 
When  at  rest,  the  ar- 
mature is  held  close  to 
the  electromagnet.  If 
the  switch  is  open,  the 
current  stops.  There 


Telegraph  key  and  sounder.    Name  the  essential 
parts  shown. 


is  no  longer  any  mag- 
netism to  hold  the  ar- 
mature and  it  is  raised  by  a  spring.     Upon  pressing  the 
key  the  current   flows,  magnetism  is  produced,    the   ar- 


376  MEANS  OF   COMMUNICATION 

mature  is  drawn  down,  and  the  blow  on  the  yoke  results  in 
a  loud  click.  The  interval  of  time  between  successive 
clicks  is  determined  by  the  length  of  time  the  key  is  kept 
closed.  A  short  interval  makes  a  "  dot,"  and  a  long  in- 
terval makes  a  "  dash."  Dots  and  dashes  in  different 
combinations  stand  for  the  letters  of  the  alphabet.  A 
short  space  of  time  follows  each  letter  and  a  longer  one  fol- 
lows each  word.  The  following  is  the  Morse  Telegraph 
Code : 

A—  H....  O.  .  u... 

jLL.  Q"LY 

Kn 
— •—  K«  «» 

L—  S... 


In  commercial  lines  where  messages  must  be  sent  long 
distances,  another  instrument,  the  relay,  must  be  used. 
The  relay  is  more  sensitive  than  the  sounder,  and  will 
operate  on  a  current  too  weak  to  operate  the  sounder. 
It  is  therefore  used  when  the  message  comes  from  long 
distances  to  close  a  local  circuit  containing  a  sounder  and 
battery. 

The  telephone.  —  The  telephone  offers  an  example  of 
the  rapidity  with  which  useful  scientific  inventions  are 
adopted  in  modern  times.  The  telephone  was  invented 
about  fifty  years  ago ;  it  has  been  in  commercial  use  about 
thirty  years,  and  to-day  there  are  over  eleven  million 
telephones  in  use  involving  the  use  of  nearly  30,000,000 
miles  of  wire.  People  in  San  Francisco  and  New  York 
can  carry  on  conversation  with  each  other  with  as  much 
ease  as  if  they  were  sitting  in  adjoining  chairs,  and  by 
wireless  telephone  conversation  can  be  carried  on  between 


HOW  THE  TELEPHONE  TRANSMITS   SOUND     377 


an  airplane  high  in  the  air  and  the  ground,  or  between 
Europe  and  America. 

Experiment.  —  To  study  the  action  of  the  telephone  transmitter. 

Materials:  Telephone  transmitter.  Four  dry  cells.  Two  electric  light 
carbons.  Wires.  Ammeter  reading  to  10  amperes. 

Method  and  Results:  Connect  the  ammeter  in  series  with  four  dry  cells 
and  transmitter  in  one  circuit.  Read  the  ammeter.  Press  the  dia- 
phragm of  the  transmitter  in,  read  the  ammeter  again.  Release  the 
diaphragm.  Result?  Disconnect. 

Replace  the  transmitter  with  the  two  carbon  pencils  and  use  two  in- 
stead of  four  cells ;  make  good  contact  by  winding  the  bare  ends  of  the 
connecting  wires  tightly  around  the  ends  of  the  carbons.  The  circuit 
is  closed  and  broken  by  bringing  the  two  carbons  together  and  separating 
them.  Touch  the  carbons  lightly,  read  the  ammeter.  Press  the  two 
carbons  firmly  together  making  better  contact.  Result? 

Conclusion:  Inside  the  transmitter  is  a  little  box  of  carbon  granules 
through  which  the  current  must  pass.  Explain  how  the  fluctuating 
current  is  produced  in  the  telephone  circuit  when  one  talks  into  the 
transmitter. 


How  the  telephone 

telephone  system  is 
very  complicated, 
and  yet  it  is  possible 
for  us  to  understand 
the  simple,  physical 
principles  under- 
lying its  use.  We 
must  first  of  all  re- 
call what  sound  is, 
how  the  voice  is  pro- 
duced, and  picture 
the  sound  waves  as 
vibrations  of  the  air 
traveling  to  the 
transmitter.  There, 


transmits  sound.  —  The  ordinary 


cLiccpTvrocgxiv, 
Cccrbon  Granule^ 


Telephone  transmitter 


378 


MEANS  OF   COMMUNICATION 


contrary  to  popular  belief,  the  sound  stops.  No  sound 
passes  over  the  telephone  wire.  Just  what  is  transmitted 
will  be  very  soon  understood.  Let  us  see  what  we  can 
learn  by  a  study  of  the  transmitter.  We  learn  from  the 
experiment  that  there  is  a  little  box  filled  with  carbon 
granules  in  the  transmitter.  These  grains  of  carbon  form 
a  part  of  an  electric  circuit,  but  offer  a  rather  high  re- 
sistance' to  the  flow  of  current.  If  the  carbon  particles 
are  pressed  closer  together,  resistance  is  decreased  and  more 
current  flows.  When  they  separate,  less  current  flows 
through  them.  If  we  were  to  compress  and  release  the 
walls  of  the  box  alternately,  a  variable  current  increasing 
with  pressure  and  decreasing  with  absence  of  pressure 
would  pass  through  the  circuit.  One  wall  of  this  carbon 
box  is  attached  to  a  thin  diaphragm  just  inside  the  mouth- 
piece of  the  transmitter.  Sound  waves  are  vibrations, 
the  air  becoming  first  more  and  then  less  dense  in  rapid 
succession.  Each  compression  pushes  the  diaphragm 
forward  and  presses  the  carbon  particles  closer  together. 
As  the  air  becomes  less  dense  the  dia- 
phragm springs  back  to  its  natural  posi- 
tion and  the  carbon  particles  separate. 
In  this  way,  a  pulsating  current  is  made 
to  pass  through  the  wire.  The  number 
of  pulsations  and  their  intensity  cor- 
respond to  the  number  of  vibrations  and 
the  intensity  of  the  sound  produced  in 
the  mouthpiece  of  the  transmitter. 


Experiment.  —  To  study  the  action  of  a  telephone 

receiver. 

Materials:  Telephone   receiver.    A   dry   cell.    Wire.     A    coarse  file.    A 
fine  file. 


HOW  THE  RECEIVER  GIVES   SOUND  WAVES     379 


Method  and  Results:  Connect  one  pole  of  the  cell  to  one  binding  post  of 
the  receiver  and  the  other  to  one  end  of  a  coarse  file.  Join  a  wire  to 
the  other  binding  post  of  the  receiver,  leaving  the  other  end  free.  Hold 
the  receiver  to  the  ear.  Run  the  free  end  of  wire  along  the  smooth 
surface  of  the  file  near  the  end.  Result?  Run  the  free  end  of  the  wire 
along  the  rough  surface  of  the  file.  Result?  What  different  effect 
is  noticed  if  a  fine  file  is  used  ?  If  the  speed  of  drawing  the  wire  along 
the  file  is  increased  ? 

Conclusion:  Unscrew  the  cap  on  the  end  of  the  receiver  to  see  the  inside 
structure  of  the  receiver.  Bear  in  mind  that  when  the  wire  is  drawn 
over  the  file  ridges  electrical  contact  is  made  only  when  the  wire  is 
touching  a  ridge.  Explain  the  result  detected  by  the  ear. 

How  the  receiver  gives  us  the  sound  waves.  —  Suppose 
the  electric  circuit  in  which  the  transmitter  is  connected 
also  includes  at  a  distance  a  telephone 
receiver.  What  will  happen  when  the 
pulsating  current  comes  to  it?  If  you 
should  unscrew  the  cap  at  the  end  of 
the  receiver  you  would  find  a  thin  soft 
iron  diaphragm  held  in  place  by  a  per- 
manent magnet.  Remove  the  dia- 
phragm and  you  will  find  a  small  coil  of 
wire  around  the  end  of  the  magnet. 
This  coil  of  wire  forms  the  part  of  the 
electric  circuit  which  carries  the  pulsating 
electric  current.  Every  time  the  cur- 
rent is  increased  the  magnetism  is  made 
stronger  and  the  diaphragm  is  drawn 
closer  to  it.  Every  time  the  current  decreases  the 
magnetism  becomes  weaker  and  the  diaphragm  springs 
back.  This  completes  the  vibration.  Vibrations  are 
made  as  often  as  the  pulsations  of  the  electric  cur- 
rent occur  and  these,  you  recall,  correspond  to  the 
number  of  vibrations  of  the  voice  in  the  transmitter 


Telephone  receiver. 


MEANS  OF  COMMUNICATION 


J^irxe 


mouthpiece.  The  vibrating  diaphragm  of  the  receiver 
sets  up  sound  waves  in  the  air  which  are  duplicates  of  those 
given  to  the  transmitter.  Thus  it  is  that  speech  is  re- 
produced at  the  other  end  of  a  telephone  line  with  no  sound, 
but  only  pulsations  of  electric  current  being  transmitted 

over  the  wires.  In  order  to 
strengthen  the  loudness  and  de- 
crease the  loss  of  electricity  along 
the  line,  an  induction  coil  is  used 
in  the  telephone  instrument  to 
"  step  up  "  the  voltage. 

Wireless.  —  Whenever  an 
electric  spark  is  produced  an 
electric  wave  through  the  ether 
results.  When  a  crystal  of  sili- 
con, galena,  or  some  other  so- 
called  "  detector  "  is  in  loose 
contact  with  a  metal  and  forms 
a  part  of  an  electric  circuit 
there  is  high  resistance  at  the 
point  of  contact,  but  when  an 
electric  ether  wave  passes  across 
this  contact  .  point,  the  resist- 
ance is  decreased  and  a  stronger 
current  flows.  This  strong  current  is  detected  by  listen- 
ing with  a  telephone  receiver  in  circuit.  This,  in  brief, 
is  the  principle  underlying  wireless  telegraphy.  In  practice, 
the  instruments  with  their  adjustment  and  operation  are 
rather  complicated.  The  explanation  of  how  a  wireless  set 
works  will  make  an  excellent  project  for  those  particularly 
interested.  The  following  experiment  illustrates  in  a 
simple  way  how  a  message  may  be  sent  and  received. 


nsmitber 


pring- 


"Receiver 


Instruments  in  a  subscriber's  tele- 
phone set. 


WIRELESS 


Experiment.  —  To  demonstrate  the  principle  of  wireless  telegraphy. 

Materials:  An  ordinary  telephone  receiver.  Dry  cell.  Two  screw 
binding  posts.  Copper  wire.  Graphite  from  "  lead "  pencil.  An 
iron  bolt  nut.  Two  pieces  of  sheet  metal.  A  small  static  machine  or 
an  induction  coil. 


deceiving 


AeT»icxl 


Apparatus  for  demonstrating  wireless. 

Method.  Receiving  end:  Screw  the  two  binding  posts  into  a  block  of 
wood  i  y  apart.  Put  a  3-inch  length  of  No.  16  bare  copper  wire  through 
the  holes  of  each  binding  post  so  that  they  lie  horizontally  and  about 
parallel  to  each  other.  Strip  the  wood  from  the  graphite  in  a  soft 
"  lead  "  pencil  to  obtain  a  2  to  3-inch  length  of  graphite.  Tie  the  bolt 
nut  to  the  center  of  this  and  lay  it  across  the  two  bare  copper  wires. 
The  weight  of  the  nut  makes  good  electrical  contact  between  the  copper 
and  the  graphite.  This  device  is  the  detector.  Connect  a  dry  cell  and 
the  telephone  receiver  in  circuit  with  the  detector.  Also  connect  wires 
to  the  binding  posts  of  the  detector;  one  to  a  metal  sheet  (aerial) 
fastened  high  in  the  room  and  the  other  to  the  ground.  The  ground  is 
easily  secured  by  connecting  to  a  water  or  gas  pipe  or  to  a  steam  pipe. 

Sending  end:  In  a  dis.tant  room  or  a  different  building  near  by,  set 
up  the  sending  apparatus.  This  may  be  a  static  machine.  If  so,  con- 
nect one  pole  to  the  ground  and  the  other  to  a  metal  plate  (the  aerial), 
as  was  done  in  the  receiving  apparatus.  Draw  the  pole  pieces  about 
$  inch  apart  and  generate  electricity.  When  a  spark  passes,  a  listener 
in  the  telephone  receiver  will  hear  a  slight  click  or  crackle  of  the  tele- 
phone diaphragm. 

If  an  induction  coil  is  used  in  place  of  the  static  machine,  adjust 
the  spark  gap  to  give  a  "  fat "  spark.  Use  the  ground  and  aerial  a? 
in  the  other  case.  Each  spark  produced  by  closing  the  key  will  make 


382 


MEANS   OF  COMMUNICATION 


an  audible  sound  in  the  telephone  receiver  at  a  considerable  distance 
away. 

The  detector  may  need  some  adjustment  such  as  moving  along  to  a 
new  position  on  the  copper  wires  or  in  bending  the  copper  wires  to  change 
the  distance  between  them. 

Conclusion:  Write  an  account  which  explains  the  science  principles  in- 
volved in  sending  and  receiving  the  message  by  the  apparatus  used. 


A  well-equipped  wireless  station. 

Wireless  has  come  to  be  considered  an  essential  equip- 
ment for  steamships  and  air  craft.  It  is  also  used  in 
commercial  life  for  carrying  messages  across  the  ocean 
between  many  different  countries.  Not  only  can  mes- 
sages be  sent  by  code  signals  but  actual  conversation  can 
be  carried  on  by  parties  thousands  of  miles  apart.  This 
is  done  by  means  of  the  wireless  telephone. 

The  newspaper.  —  Perhaps  no  medium  of  communica- 
tion exerts  a  wider  influence  upon  our  thoughts  and  ac- 
tions than  the  newspapers  and  periodicals.  It  is  a  far 
cry  from  the  crude  press  of  Gutenberg  which  would  give 
half  a  dozen  single  sheets  an  hour,  to  the  modern  Hoe  press 


SENDING  PICTURES  AND  WRITING  BY  WIRE      383 

which  turns  out  our  newspapers  with  almost  lightning 
rapidity.  The  gathering  of  news,  the  editing,  the  type- 
setting, the  plate  making,  the  printing  and  delivering  of 


Our  newspapers  are  printed  by  means  of  very  complicated  machines. 

the  paper  so  that  one  can  buy  a  paper  containing  a  printed 
account  of  the  various  happenings  within  a  few  hours  after 
they  occur  make  up  one  of  the  marvels  of  modern  achieve- 
ments. It  is  said  that  half  an  hour  after  the  death  of  Queen 
Victoria  newspapers  telling  of  her  death  were  being  sold 
on  the  streets  of  New  York. 

Sending  pictures  and  writing  by  wire.  —  Several  suc- 
cessful devices  have  been  invented  by  which  pictures  can 
be  sent  over  telegraph  lines.  The  processes  are  too  com- 
plicated for  description  here.  The  telewriter  is  a  modern 
instrument  by  which  a  person  can  write  a  message  and 
have  it  written  instantly  in  his  own  handwriting  hundreds 
of  miles  away.  Telegrams  and  drawings  are  as  easily 
reproduced  as  the  writing.  The  telewriter  depends  in  its 
action  upon  a  properly  adjusted  system  of  resistances  and 
electromagnets.  The  copy  made  by  the  receiving  instru- 
ment is  done  with  a  pen  which  goes  through  the  actual 


MEANS  OF  COMMUNICATION 

operations  of  a  similar  pen  in  the  hand  of  the  sender.  One 
cannot  read  of  all  these  marvels  without  thinking  of  the 
first  message  sent  over  the  telegraph  by  Morse :  "  What 
hath  God  wrought!" 


SCORE  CARD.    TRANSPORTATION  AND  COMMUNICATION 


PERFECT 
SCORE 

MY 
SCORE 

STREETS  AND  ROADS 
Surface  of  type  well  adapted  to  location  and  kind  of 
traffic  (5) 
Roadway  of  ample  width  and  lined  with  trees  (5) 
Kept  in  good  repair  and  clean  (5) 
Bridges  conveniently  located  and  well  kept  (5) 

20 

RAILWAY 

One  or  more  railway  lines  in  the  community,  with 
local  and  express  trains  (5) 
A  freight  depot  in  the  town  (5) 
House  express  collection  and  delivery  (5) 

15 

STREET  CONVEYANCES 
Frequent  street  car  or  jitney  service  locally  and  to 
near-by  towns  (5) 
Cars  or  jitneys  adequate  for  traffic  without  over- 
crowding (5) 
Cost  of  travel  in  proportion  to  distance  (5) 
Satisfactory  bus  or  taxi  service  (5) 

20 

WATER  TRANSPORTATION 
A  good  harbor  for  ocean  traffic  (5) 
Lake  or  river  transportation  for  fifty  or  more  miles 
(2i) 
Canal  extensively  used  (2^) 

10 

MAIL  SERVICE  AND  NEWSPAPERS 
At  least  two  collections  and  deliveries  daily  (5) 
Daily  paper  published  in  town   (10);    within    10 
miles  (5) 

IS 

TELEGRAPH 
Day  service  (5) 
Night  service  (5) 

10 

TELEPHONE  AND  SIGNAL  SERVICE. 
Local  and  long  distance  telephone  (5) 
Fire  alarm  box  signal  system  (25) 
Police  signal  service  (2^) 

10 

TOTAL 

100 

SCORE  CARD  385 


REFERENCE   BOOKS 

Adams,  Harper's  Electricity  Book  for  Boys.     Harper  and  Brothers. 

Baker,  Boys'  Book  of  Inventions.     Doubleday,  Page  and  Company. 

Carson,  History  of  the  Telephone.     A.  C.  McClure  Company. 

Collins,  Book  of  Electricity.     D.  Appleton  and  Company. 

Collins,  The  Book  of  Wireless.     D.  Appleton  and  Company. 

Cressey,  Discoveries  and  Inventions  of  the  Twentieth  Century.  E.  P.  Button  Com- 
pany. 

D  arrow,  The  Boy's  Own  Book  of  Great  Inventions.    The  Macmillan  Company. 

Doubleday,  Stories  of  Inventions.    Doubleday,  Page  and  Company. 

Holland,  Historic  Inventions.     G.  W.  Jacobs  and  Company. 

Meadowcroft,  A-B-C  of  Electricity.     Harper  and  Brothers. 

Massie  and  Underbill,  Wireless  Telegraphy  and  Telephony.  D.  Van  Nostrand 
Company. 

Maule,  Boys'  Book  of  New  Inventions.     Grosset  and  Dunlap. 

Morgan,  Boy  Electrician.     Lothrop,  Lee,  and  Shepard  Company. 

Perry,  Four  American  Inventors.     American  Book  Company. 

Shafer,  Harper's  Everyday  Electricity.     Harper  and  Brothers. 

Towers,  Masters  of  Space.     Harper  and  Brothers. 

Weir,  The  Young  Telephone  Inventor.     Wild  and  Company. 

Wright,  Stories  of  American  Progress.     Charles  Scribner's  Sons. 


H.  W.  CIV.  SCI.  COMM. 25 


PART   VI.    HOW    LIFE    ON   THE 
EARTH   HAS   IMPROVED 

CHAPTER  XXV 

HOW    PLANTS    AND    ANIMALS    HAVE    BEEN 
IMPROVED 

Problems.  —  i.    To  understand  how  life  comes  from  life. 

2.  To  learn  how  pollination  is  brought  about  in  flowers. 

3.  To  find  out  what  results  from  pollination. 

4.  To  understand  the  meaning  of  the  terms  heredity  and 
variation. 

5.  To  understand  the  meaning  of  the  work  done  by  some 
great  investigators  in  heredity. 

6.  To  know  something  of  Gregor  Mendel  and  his  law  of 
inheritance. 

7.  To  learn  something  of  the  work  of  the  Department  of 
Agriculture. 

Experiments. —  i.   To  learn  about  the  structure  and  work  of  the  parts 
of  a  flower. 

2.  To  study  cross-pollination  in  flowers. 

3.  To  study  the  structure  and  growth  of  pollen. 

4.  To  determine  if  there  is  individual  variation  in  any  one  measure- 
ment of  the  members  of  my  class. 

5.  To  understand  how  artificial  selection  is  made. 

6.  To  show  how  hybridizing  is  accomplished. 

Project  I.  —  To  SEE  HOW  PLANTS  ARE  IMPROVED  IN  YOUR  COM- 
MUNITY. 

386 


TYNDALL'S  EXPERIMENT  387 

1.  To  make  a  study  of  the  part   played  by  different  agents  in 
cross-pollination  of  garden  and  other  crops  in  your  vicinity. 

2.  To  learn  what  methods  of  plant  improvement   are  practiced 
by  the  farmers  or  florists  in  your  neighborhood. 

3.  To  make  a  study  of  the  processes  used  in  breeding  some  par- 
ticular plant  in  your  own  garden. 

Life  from  life.  —  We  have  heard  the  statement  that  all 
life  comes  from  life.  We  know  that  this  is  true,  and  yet 
not  so  many  centuries  ago  people  thought  that  flies  came 
from  rotted  meat  and  frogs  from  scum  on  ponds.  Per- 
sons are  heard  to  say,  even  to-day,  that  toads  rain  down 
and  that  some  insects  are  formed  from  the  earth.  It  was 
not  until  the  middle  of  the  last  century  that  an  Italian 
named  Redi  proved  that  flies  did  not  come  from  rotted 
meat.  He  did  this  in  the  following  way.  Taking  three 
deep  dishes  he  placed  some  stale  meat  in  the  bottom  of 
each.  One  he  left  open,  a  second  he  covered  with  fine 
netting,  and  a  third  he  covered  with  parchment  paper 
so  that  no  odor  could  pass  out.  He  observed  after  a  short 
time  that  maggots  appeared  in  the  open  dish,  but  in  neither 
of  the  others.  He  then  examined  the  netting  carefully 
and  found  the  eggs  of  flies  on  it.  We  can  reason  from 
this  experiment,  knowing  what  we  do  about  the  habits  of 
flies,  that  they  were  attracted  by  the  decayed  meat,  laid 
their  eggs  in  the  meat  in  the  first  dish,  laid  their  eggs  as 
near  to  it  as  they  could  in  the  netting  in  the  second  dish, 
but  were  not  attracted  to  the  third  dish  at  all  because 
there  was  no  odor  from  it. 

Tyndall's  experiment. — As  late  as  1876  many  people 
believed  that  germs  came  spontaneously  from  water  or 
certain  decayed  substances.  Professor  Tyndall,  by  means  of 
the  apparatus  shown  in  the  diagram,  convinced  scientists 


388 


HOW  PLANTS  AND  ANIMALS  IMPROVED 


that  there  was  no  such  thing  as  spontaneous  generation  of 
life.  He  made  a  box  which  had  a  false  bottom  through 
which  test  tubes  of  various  sterile  substances  could  be 

placed.  This  box  had 
two  glass  sides  through 
which  rays  of  light  could 
pass.  The  inside  of  the 
box  was  carefully  cov- 
ered with  oil  or  vase- 
line so  that  dust  in  the 
air  inside  the  box  would 
stick  to  the  sides.  Air 
was  admitted  into  the 
box  through  small, 
curved  glass  tubes. 
These  tubes  were  also 
greased  on  the  inside 
and  were  so  made  that 
no  dust  could  find  its 


TyndalTs  apparatus. 


way  into  the  box.  When  the  air  within  the  box  was  entirely 
free  from  dust  there  was  never  any  growth  of  bacteria  in 
the  substances  in  the  test  tubes.  This  proved  conclusively 
that  bacteria  were  introduced  into  substances  in  the  tubes 
by  means  of  dust  in  the  air.  Different  experiments  by 
Louis  Pasteur  proved  that  the  small  organisms  called 
bacteria  did  not  come  into  existence  without  previously 
coming  from  other  living  germs  of  the  same  kind. 

Structure  of  living  things.  —  We  have  already  spoken  of 
the  growth  of  bacteria.  We  found  that  these  little  plants, 
much  too  small  to  be  seen  with  the  naked  eye,  are  in  reality 
individual  organisms.  These  structures,  which  we  call 
cells,  are  the  units  out  of  which  living  matter  is  formed. 


ASEXUAL  REPRODUCTION 


389 


When  we  look  at  a  distant  brick  building,  we  can  only  see 
that  it  is  red.  But  if  we  focus  a  field  glass  or  a  telescope 
upon  it,  we  can  see  the  individual  bricks  out  of  which 
it  is  made.  In  the  same  way  if  we  look  at  a  large  plant 
or  animal  we  cannot  see  its  formation,  but  if  we  were  able 
to  cut  a  very  small  slice  from  the  plant  or  animal,  mount 
it  under  a  microscope,  and  examine  it,  we  would  see  that 
it  was  made  of  little  box-like  structures,  the  cells. 

Structure  of  cells.  —  It  has  taken  a  great  many  years  of 
study  to  discover  that  the  cell  is  the  unit  of  structure  in 
both  plants  and  animals.  Cells  in  all 
kinds  of  living  things  are  made  of  proto- 
plasm. As  we  look  at  the  structure  of 
a  plant  we  find  this  living  matter  is  not 
so  evident  as  in  the  cells  of  living  ani- 
mals because  the  plant  cells  have  thick 
walls  of  cellulose.  If  the  contents  of  the 
cell  be  carefully  stained  with  certain  A  ceii;  c.w.,  cell  wall; 

.  -IT  •  n>  nudeus;    ch.,  chro- 

dyes,  we  find  it  invariably  contains  a      mosomes;   p.,  proto- 
plasm, 
small  darker  stained    body  called   the 

nucleus,  within  which  are  found  certain  tiny  bodies  which 
color  deeply  and  hence  are  called  chromosomes  (color-bear- 
ing bodies). 

Asexual  reproduction.  —  When  cells  multiply,  the  nucleus 
divides,  half  of  the  chromosomes  go  into  one  of  the  new 
nuclei  and  half  into  the  other.  The  cell  body  separates 
and  two  cells  are  formed  out  of  the  original  one.  This 
method  of  reproduction  of  living  organisms  is  called  asexual 
and  occurs  only  in  very  simple  forms  of  life.  Likewise, 
the  growth  of  a  plant  or  a  tree  or  a  frog  or  a  baby  is  always 
dependent  upon  the  multiplication  of  cells  making  up  the 
body  of  the  living  thing.  This  growth  depends  upon  the 


3QO        HOW  PLANTS  AND  ANIMALS  IMPROVED 


nutrition  of  the  individual  plant  or  animal.  If  it  is  well 
nourished,  if  plenty  of  food  is  absorbed  by  the  cells,  and  if 
they  change  this  food  into  living  matter,  then  the  cells  will 

grow  rapidly  and 
the  body  will  in- 
crease in  weight. 
It  is  a  matter  of 
common  knowl- 
edge that  if  one's 
digestion  is  not 
good  or  if  for 
some  reason  the 
cells  of  the  body 
do  not get  enough 
nourishment,  then 
their  growth  is 
person  does  not  gain  and  may  even  lose 


ages  in  the  division  of  one  cell  into  two.  The  nucleus 
divides  first ;  the  chromosomes  split  and  the  parts  go 
in  equal  numbers  to  each  of  the  new  cells. 


slow  and  a 
weight. 

Sexual  reproduction.  —  But  there  is  another  method  by 
which  living  things  reproduce.  Not  all  plants  are  produced 
by  planting  slips  or  buds  nor  by  fission  as  explained  above. 
As  a  matter  of  fact  most  plants  that  we  know  of  come 
from  seeds.  In  most  animals  the  young  do  not  bud  or 
break  off  from  the  parents,  but  as  in  the  case  of  the  frogs 
or  birds  the  young  develop  from  eggs.  Let  us  see  how 
this  kind  of  reproduction,  which  is  called  sexual,  is 
brought  about. 

The  relation  of  bees  to  flowers.  —  We  have  all  watched 
a  bee  as  it  visited  some  bright  flower,  and  perhaps  have 
noticed  just  what  happened.  The  bee  lights  on  the  flower 
and,  standing  upon  some  one  of  the  outer  parts,  sticks  its 
head  down  into  the  middle  of  the  flower.  Its  head  bears  a 


STRUCTURE  OF  A  SIMPLE  FLOWER 


391 


long  beak  or  proboscis,  and  if  we  watch  the  little  animal 
carefully  we  find  it  is  trying  to  get  some  liquid  matter  that 
is  stored  within  the  flower,  or  that  it  is  engaged  in  gather- 
ing yellow  masses  of  dust  from  certain  parts  of  the  flower. 
Let  us  now  examine  a  similar  flower  carefully  to  see  just 
what  the  bee  is  after. 

Experiment.  —  To  learn  about  the  structure  and  work  of  the  parts  of  a  flower. 

Materials:  Any  large  flower,  preferably  a  simple  flower.     Hand  lens. 

Method:  Carefully  examine  parts  of  flower. 

Observations:  Notice  that  the  flower  is  built  with  the  parts  in  circles. 
How  many  parts  in  the  out-most  circle?  Of  what  color?  They  are 
called  sepals.  Collectively  they  make  up  the  calyx.  The  parts  in 
the  next  circle  are  called  petals.  How  many  parts  did  you  find  ?  Do 
they  have  color?  Together  they  form  the  corolla.  Notice  the  little 
knobbed  structures  next  in  order.  They  are  called  stamens.  The  stalk 
is  called  the  filament;  the  knob,  the  anther.  The  yellow  dust  is  called 
pollen.  Use  a  lens  and  see  how  the  pollen  gets  out  of  the  anther. 

The  middle  part  of  the  flower  is  called  the  pistil.  The  enlarged 
base  is  the  ovary;  the  s'alk  h  the  style;  the  tip,  which  is  sticky,  is  the 
stigma.  Pollen  will  grow  on  the  stigma.  How  can  pollen  get  from  the 
stamens  to  the  ovule?  Cut  a  cross-section  through  the  ovary.  The 
little  structures  we  see  inside  are  called  ovules.  Within  each  ovule  is  an 
£££  C'll  which  is  too  small  to  be  seen  without  a  microscope.  This  egg 
cell  under  certain  con- 


ditions  will  develop 
into  a  baby  plant. 
Conclusions:  Which 
parts  of  the  flower 
are  essential  for  the 
production  of  seeds? 
What  then  are  the 
essential  organs  of  the 
flower? 

Structure      of     a 
simple      flower.  - 
If  you  examine   al- 
most any  large  flower,  you  will  find  as  you  look  at  it  from 


Parts  of  a  flower. 


3Q2        HOW  PLANTS  AND  ANIMALS  IMPROVED 

above  that  it  seems  to  be  in  circles  or  whorls.  Outside  are 
some  green,  leaf -like  structures  which  we  call  sepals. 
Within  this  is  found  another  circle  of  parts,  usually  brightly 
colored  and  sometimes  quite  irregular  in  shape.  These 
are  called  petals,  or,  taken  together  they  form  the  corolla. 
Still  farther  within  the  flower  are  a  number  of  little  stalks 
bearing  at  the  end  tiny  boxes  which  contain  the  pollen  or 
yellow  dust  just  spoken  of.  These  structures  are  called 
the  stamens,  the  stalk  is  the  filament,  the  box  holding  the 
pollen,  the  anther.  In  the  very  center  of  the  flower  is  a 
structure  shaped  somewhat  like  an  Indian  club  with  the  big 
portion  at  the  bottom  of  the  flower.  This  structure  is 
called  the  pistil.  We  shall  see  later  it  is  a  very  important 
part  of  a  flower.  Many  flowers  get  along  without  the 
sepals  and  petals,  having  only  the  essential  organs,  the 
stamens  and  pistils. 

What  the  bee  is  after.  —  If  we  should  examine  the  lower 
part  of  the  cup  of  the  flower  with  a  hand  lens  we  would 
find  little  glistening  drops  of  moisture.  We  have  all 
pulled  a  honeysuckle  and  sucked  this  liquid  from  the 
bottom  of  the  tube.  It  is  sweet  and  is  called  nectar.  The 
bee  visits  the  flower  to  obtain  nectar  which  it  uses  in 
making  honey,  and  pollen  which  it  uses  in  feeding  the 
young. 

Experiment.  —  To  study  the  structure  and  growth  of  pollen. 
Materials:   Pollen   of  tulip,  sweet  pea,  or  nasturtium.     Sugar  solution, 
3%,    10%,    15%.     Bell     jar,   sponge,   hand    lens,    compound    micro- 
scope. 

Method:  Dust  some  tulip  pollen  into  a  3%  sugar  solution,  a  drop  of 
which  has  first  been  placed  on  a  glass  slide.  Do  the  same  with  sweet 
pea  or  nasturtium,  and  a  10%  and  15%  sugar  solution.  Place  slides 
and  a  moistened  sponge  under  a  small  bell  jar.  Examine  every  twenty- 
four  hours  with  low  power  lens  of  compound  microscope. 


WHAT  THE   POLLEN   DOES 


393 


Observations:    Notice  the  small  tube-like  structures  growing  out  of  pollen 

grains.     These  are  the  pollen  tubes  and  contain  sperm  cells. 
Conclusions:   i.   What  made  the  pollen  tube  grow? 

2.   Under  what  natural  conditions  might  pollen  tubes  grow? 

What  the  pollen  does.  —  If  we  were  to  examine  the  grains 
of  pollen  under  a  microscope  we  would  find  that  they  con- 
tained one  or  more  cells,  depending  upon 
the  age  of  the  pollen  grains.  Some  of  these 
pollen  grains  when  placed  in  a  weak  solu- 
tion of  sugar  and  water  will  sprout,  giv- 
ing rise  to  little  tubes  looking  very  much 
like  root  hairs.  These  pollen  tubes  contain 
cells,  one  of  which  is  known  as  a  sperm 
cell.  Examination  of  the  top  of  the  pistil 
shows  the  surface  to  be  moist  and  sticky. 
It  evidently  throws  out  a  fluid  somewhat 

like  a  sir- 
up.    If  a 

pollen  grain  lights  upon 
this  sticky  surface  called 
the  stigma,  it  will  usually 
germinate,  the  pollen 
tube  going  down  the 
stalk  of  the  pistil  and 
eventually  finding  its  way 
into  a  little  structure  in 
the  base  of  the  pistil, 
called  the  ovule.  Within 
this  ovule  are  found  a 
number  of  cells,  one  of 
which  is  an  egg  cell.  As 
the  pollen  tube  grows 


'Pollen  drain  otv 


gg  cell 


Pollen  grain  and 
tube.  Section  on 
right  shows 
sperm  cell  pass- 
ing down  the 
tube. 


Fertilization  of  a  flower. 


394        HOW  PLANTS  AND  ANIMALS  IMPROVED 


downward  it  takes  with  it  a  single  sperm  nucleus  which 
under  favorable  conditions  unites  with  the  egg  nucleus. 
This  union  is  called  fertilization.  The  ovule  grows  rap- 
idly larger,  the  basal  part  of  the  pistil  containing  it  be- 
comes thicker,  and  the  cells  multiply  rapidly  and  thus 
a  seed  is  formed.  This  seed  is  usually  contained  within 
the  thickened  part  of  the  pistil  which  goes  to  form  a  fruit. 

Experiment.  —  To  study  cross-pollination  in  flowers. 

Method:  Take  a  field  trip  where  flowers  are  abundant  and  notice  the 
following : 

Observations:  Are  flowers  being  visited  by  insects?  If  so,  what  insects? 
Do  bees  visit  flowers  of  one  sort  or  of  different  sorts  in  order?  Make 
a  careful  study  of  this  with  the  bee.  With  the  butterfly,  or  other 
insects.  Do  insects  seem  to  know  color?  Do  they  seem  to  prefer 
one  color  to  another?  Can  you  discover  any  means  by  which  the  flowers 
might  attract  an  insect?  Insects  can  probably  smell  and  taste  as  well 
as  see.  Do  you  find  any  peculiar  shapes  in  flowers  which  seem  to  offer 
a  resting  place  for  insects?  If  so,  does  the  pollen  from  such  flowers 
become  attached  to  any  part  of  the  insect?  Catch  two  or  three  differ- 
ent insects.  Use  a  hand  lens  to  see  if  any  pollen  is  caught  on  any  part 
of  their  bodies.  Could  this  pollen  be  carried  from  one  flower  to  another 
of  the  same  kind  ? 

Conclusions:   i.   What  do  insects  get  from  flowers? 

2.  What  do  insects  give  to  flowers? 

3.  How  might  this  be  of  use  to  plants? 

Cross-pollination.  —  Pollen  will  germinate  only  on  flowers 

of  the  kind  on  which 
it  grew,  or  rarely  on 
those  which  are 
nearly  related  to  it. 
The  bee,  therefore, 
when  it  takes  pollen 
on  its  hairy  legs  or 
body  from  one  flower 
Cross-poiiination.  to  another  of  the 


THE  DEVELOPMENT  OF  AN  EMBRYO 


395 


same  kind  transfers  the  pollen  grains  to  a  place  where 
they  can  germinate.  This  process  is  called  cross-pollina- 
tion. It  has  been  found  by  biologists  that  plants  are 
usually  healthier  and  stronger  if  they  grow  from  seeds 
developed  in  flowers  which  have  been  fertilized  by  grains 
of  pollen  brought  from  anthers  of  one  flower  to  the  pistil 
of  another  flower  of  the  same  kind. 

Some  ways  in  which  cross-pollination  is  brought  about.  — 
It  would  take  a  long  chapter  to  tell  of  all  the  structures 
which  nature  has  devised  in  order  to  bring  about  cross-pol- 
lination. Flowers  have  different  forms,  often  making  at- 
tractive footholds  for  insects  so  that  they  will  come  to  visit 
and  thus  carry  pollen  from  one  flower  to  another.  Bright 
colors  are  means  of  advertising  to 
the  insect  that  the  flower  contains 
nectar  and  pollen.  Often  a  sweet 
odor  plays  an  important  part  in 
attracting  the  bee,  and  some  flowers 
which  are  pollinated  by  flies  have 
an  unpleasant  odor  almost  like 
rotting  meat.  Frequently  flowers 
have  remarkable  devices  such  as 
shown  in  the  illustration,  which 
enable  them  to  be  sure  of  either 
self-  or  cross-pollination.  Besides,  in- 
sects, birds,  the  wind,  water,  or  man 
himself  may  be  a  means  of  carrying 
pollen  from  one  flower  to  another. 

The  development  of  an  embryo.  —  After  the  egg  cell 
has  united  with  the  sperm  cell  a  single  cell  is  formed,  but 
almost  immediately  this  cell  divides  into  two,  then  these 
two  into  four,  four  into  eight,  and  so  on,  until  within 


Notice  that  the  bee's  head  rubs 
against  the  anthers  (A)  and 
later  against  the  stigma  (5) 
as  he  presses  forward  to  secuie 
the  nectar  (N).  How  may 
this  aid  in  self-pollination? 
If  the  bee  visits  other  flow- 
ers of  the  same  kind,  might 
cross- pollination  result?  Ex- 
plain. 


396        HOW  PLANTS  AND  ANIMALS  IMPROVED 

the  seed  a  little  baby  plant  or  embryo  is  formed.  This 
embryo  remains  dormant  until  such  time  as  the  seed  is 
placed  in  favorable  conditions  for  germination  or  growth. 
We  know  that  plants  in  the  garden  require  a  certain  amount 
of  warmth,  water,  and  soil.  Under  such  conditions  the 
baby  plant  within  the  seed  is  awakened  to  activity  and 
starts  to  grow.  Eventually  it  will  produce  flowers,  and 


Plants  and  animals  both  develop  into  embryos. 

if  the  egg  cells  are  fertilized  these  flowers  will  then  produce 
fruits  containing  seeds.  These  seeds  in  turn  will  give  rise 
to  new  plants. 

Development  in  animals.  —  Nearly  every  boy  and  girl 
has  seen  a  mass  of  freshly  laid  frog's  eggs.  These  eggs 
are  laid  in  water  in  the  early  spring  by  the  female  frog. 
The  male  frog  then  places  some  sperm  cells  on  the  eggs. 
If  a  sperm  cell  unites  with  an  egg  cell  then  that  fertilized 
egg  cell  will  develop  into  a  little  tadpole  or  baby  frog.  If 
you  will  examine  a  mass  of  frog's  eggs  laid  in  the  early 
spring,  you  will  doubtless  see  that  these  eggs  are  in  the  pro- 
cess of  division.  Just  as  in  the  flower,  the  fertilized  egg  di- 
vides first  into  two,  then  into  four,  then  into  eight,  then 


DEVELOPMENT  IN  ANIMALS 


397 


Development  of  a  frog,  i,  two-cell  stage;  2,  four-cell  stage;  3,  8  cells  are  formed, 
notice  the  upper  cells  are  smaller;  in  (4)  the  lower  cells  are  seen  to  be  much  larger 
because  of  the  yolk ;  5,  the  egg  has  continued  to  divide  and  has  formed  a  gastrula ; 
6,  7,  the  body  is  lengthening,  head  is  seen  at  the  right-hand  end ;  8,  the  young  tadpole 
with  external  gills;  9,  10,  the  gills  are  internal,  hind  legs  beginning  to  form;  n,  the 
hind  legs  show  plainly;  12,  13,  14,  later  stages  in  development;  15,  the  adult  frog. 
Figures  i,  2,  3,  4,  5,  6,  and  7  are  very  much  enlarged.  (Drawn  after  Leukart  and 
Kny.) 


398        HOW  PLANTS  AND  ANIMALS  IMPROVED 

sixteen  cells.  So  these  cells  keep  on  multiplying  until 
within  a  couple  of  days  if  the  weather  is  warm  the  embryo 
of  the  frog  begins  to  elongate.  In  another  day  the  little 
tadpole  wriggles  out  of  the  jelly  in  which  the  egg  was  placed 
and  soon  goes  swimming  about  after  food.  Almost  every 
boy  and  girl  knows  that  these  little  tadpoles  after  a  time 
grow  hind  legs,  then  front  legs  develop  while  at  the  same 
time  the  tail  is  being  absorbed  into  the  body.  Eventually 
we  have  the  young  frogs.  Not  until  the  female  frogs  are 
adults  are  they  able  to  lay  eggs  and  thus  pass  on  their 
kind  to  future  generations. 

Heredity  and  variation.  —  If  you  will  go  out  into  the 
garden  some  morning  and  look  at  a  row  of  pea  or  bean 
plants  that  are  coming  up  you  will  notice  that  they  are  all 
very  much  alike.  They  have  the  same  shaped  leaves,  the 
same  general  appearance  of  stem,  the  pea  or  bean  pods  will 
be  more  or  less  of  the  same  color  and  appearance,  and  the 
seeds  will  all  be  generally  alike  in  shape,  size,  or  color. 
If  you  were  to  plant  these  seeds  they  would  produce 
more  plants  like  the  plants  from  which  these  seeds  came. 
This  likeness  of  child  to  parent  is  due  to  -what  we  call 
heredity.  But  if  you  were  to  examine  the  plants  more 
closely  you  would  find  that  every  plant  is  slightly  dif- 
ferent from  its  neighbor.  They  differ  in  the  tallness 
or  shortness  of  the  stem,  in  the  size  of  the  pod,  in  the 
number  of  peas  or  beans  produced  in  the  pod,  and  in  a 
hundred  other  ways  which  could  only  be  detected  by 
fine  measurements.  These  plants  have  the  same  condi- 
tions of  soil,  moisture,  and  air.  The  factors  of  their  en- 
vironment may  be  the  same,  and  yet  the  plants  differ. 
This  tendency  to  differ  among  plants  and  animals  is  called 
variation. 


VARIATION  AND   ITS  USE  TO  MEN  399 

Experiment.  —  To  determine  if  there  is  individual  variation  of  any  one 
measurement  of  the  members  of  my  class. 

Materials:  String.     Rule. 

Method:    With  the  string  carefully  measure  the   circumference   of   the 

right  wrist  of  a  member  of  the  class  and  let  him  measure  yours. 
Observations :  Hand^your  measurement  in  inches  on  a  piece  of  paper  to  one 

member  of  the  class  who  will  tabulate  the  figures  on  the  board.     Make 

a  graph  showing  the  individual  variations. 
Conclusion:  Is  there  variation  in  this  measurement  among  the  members 

of  your  class? 

Variation  in  the  classroom.  —  In  the  same  way  if  we 
observe  the  members  of  the  class  we  see  that  the  boys  and 
girls  are  built  on  the  same  general  model,  and  no  doubt  in 
many  ways  they  closely  resemble  their  fathers  and  mothers, 
and  in  some  respects  their  grandparents  or  great  grand- 
parents. But  on  the  other  hand,  each  individual  member 
varies  in  many  different  ways.  We  all  know  that  if  we 
were  to  take  finger  prints  of  each  member  of  the  class  no 
two  would  be  alike.  These  two  great  factors  of  heredity 
and  variation  have  done  much  to  change  the  life  of  plants 
and  animals  on  the  earth. 

Variation  and  its  use  to  men.  —  For  a  good  many  years 
variation  has  been  noticed  and  has  been  made  use  of  in  a 
practical  way  by  plant  and  animal  breeders  although  they 
have  not  known  any  exact  laws  with  which  to  work.  Yet 
they  have  succeeded,  by  mating  plants  or  animals  with  cer- 
tain desired  variations,  in  producing  better  offspring. 

Experiment.  —  To  understand  how  artificial  selection  is  made. 

Materials:  Corn  on  the  ear.     Shallow  box  and  sawdust. 

Observations:  Compare  several  different  ears  of  corn  and  select  one  ear 
which  has  the  most  even  rows,  largest  kernels.  Suppose  this  ear  came 
from  a  plant  bearing  but  few  ears;  would  you  select  it  for  planting? 
Now  select  one  of  the  poorest  ears,  judging  by  the  same  standards  as 
above.  Place  equal  number  of  kernels  from  each  ear  in  planting  box. 


400        HOW  PLANTS  AND  ANIMALS  IMPROVED 

Note  the  percentage  which  grow.     The  appearance  of  corn  plants  on 
the  average  of  two,  three,  and  four  weeks. 
Conclusions:   i.   How  would  you  select  corn  seed  for  planting  ? 

2.   Do  these  experiments  give  sufficient  evidence  for  selection  ? 


Types  of  corn.     From  left  to  right:  pod  corn,  soft  corn,   pop  corn,  sweet  corn,  flint 
corn,  dent  corn.     (After  Moore  and  Halligan.) 


Charles  Darwin.  —  In  the  middle  of  the  last  century,  a 
great  Englishman,  Charles  Darwin,  was  one  of  the  first  to 
realize  the  practical  uses  of  variation  and  heredity.  He 
knew  that  although  plants  and  animals  were  like  their 
ancestors  they  also  varied  from  them.  In  nature  the 
variations  which  seem  to  fit  a  plant  or  animal  for  its  own 
environment  were  the  ones  that  were  handed  down  to 
another  generation.  Darwin  thought  if  nature  thus  seized 
upon  favorable  variations,  then  man  could  select  favorable 
variations,  and  by  care  could  breed  for  the  characters  that 


WHY   PLANTS   AND   ANIMALS  BREED   TRUE     401 

he  desired.  Such  artificial  selection  is  seen  in  everyday 
farming.  The  boy  and  girl  who  belongs  to  a  corn  club 
and  who  selects  the  best  corn  for  planting  by  means  of 
testing  is  practicing  artificial  selection.  By  means  of 
selective  planting  such  as  this  the  farmers  have  put  mil- 
lions of  dollars  each  year  into  their  pockets  and  have  made 
the  cereal  crops  of  this  country  known  the  world  over. 

Mutations.  —  Rather  recently  a  Dutchman  named  Hugo 
de  Vries,  while  working  with  primroses,  discovered  that  in 
breeding  these  plants  certain  ones  were  produced  which  dif- 
fered widely  from  the  parent  plant.  The  seeds  of  these  prim- 
roses when  planted  produced  plants  exactly  like  the  parents. 
Plants  which  thus  arise  are  called  mutants.  In  1862  a  Mr. 
Fultz  of  Philadelphia,  while  passing  through  a  field  of  wheat, 
found  three  heads  of  wheat  which  had  no  chaff.  He  was  a 
plant  breeder  and  recognized  the  value  of  these  three 
beardless  wheat  heads.  He  took  the  grains  out  carefully, 
sowed  them  by  themselves,  and  as  a  result  produced  a  strain 
of  beardless  wheat  now  known  as  the  Fultz  wheat.  This 
is  an  example  of  how  a  mutant  can  be  used  in  ordinary  agri- 
cultural work.  It  should  be  the  ambition  of  every  boy 
and  girl  interested  in  agriculture  to  watch  carefully  for  such 
favorable  variations,  to  preserve  them  carefully  and  to  plant 
the  seeds  from  these  plants  in  hopes  that  the  desirable 
quality  may  be  preserved. 

What  causes  plants  and  animals  to  breed  true.  —  We 
have  already  seen  that  plants  and  animals  are  made  of 
cells.  We  have  furthermore  seen  that  these  cells  are  of 
two  kinds,  the  ordinary  cells  of  the  body  which  give  rise 
to  stems  and  leaves  and  roots  of  plants  and  the  flesh  and 
blood  of  animals,  and  another  kind  of  cell  known  as  the 
sex  or  germ  cells.  These  germ  cells  are  set  apart  at  a  very 

II.  W.  CIV.  SCI.  COMM.  26 


402        HOW  PLANTS  AND  ANIMALS  IMPROVED 

early  stage  in  the  life  of  the  plant  or  animal  and  are  the 
bearers  of  heredity.  It  has  been  pretty  well  determined  by 
means  of  careful  experiments  that  the  tiny  structures  we 
call  chromosomes  within  the  nucleus  of  the  cell  contain  the 
determiners  of  the  qualities  which  may  be  passed  from 
parent  plant  to  offspring  or  from  animal  to  animal. 

Germ  cells.  —  It  has  also  been  found  that  in  preparing 
for  the  process  we  call  fertilization  half  of  the  chromosomes 
of  the  male  cell  and  half  of  the  chromosomes  of  the  female 
cell  are  eliminated,  so  that  when  the  two  cells  combine  to 
form  a  fertilized  egg  it  contains  the  whole  number  of 
chromosomes  for  that  particular  plant  or  animal.  If 
the  chromosomes  carried  the  determiners  of  the  character- 
istics which  are  inheritable,  then  it  is  easy  to  see  that  a 
fertilized  egg  would  contain  determiners  from  both  parents. 
In  this  way  each  of  us  has  received  the  determiners  which 
give  us  certain  characteristics  which  have  been  handed 
down  from  mother  or  father,  grandmother  or  grandfather, 
or  even  from  some  far  distant  ancestor.  This  subject  is  of 
vital  importance  to  all  of  us,  and  you  will  study  more  about 
it  when  you  take  up  the  subject  of  biology  later  in  your 
school  course. 

Gregor  Mendel.  —  About  fifty  years  ago  there  lived  in 
an  Austrian  monastery  a  monk  named  Gregor  Mendel. 
He  worked  in  his  little  monastery  garden  for  a  good  many 
years  breeding  peas.  For  a  long  time  his  work  was  un- 
known, but  a  little  more  than  twenty  years  ago  it  was  sud- 
denly called  into  prominence  by  work  done  in  this  country 
and  in  Europe,  which  indicated  that  he  had  discovered  a 
law  by  which  heredity  works. 

The  law  of  unit  characters.  —  He  found  first  of  all  that 
the  plants  with  which  he  worked  handed  down  certain 


THE  LAW  OF  SEGREGATION 


403 


fixed  characteristics  such  as  the  color  of  the  peas,  the 
shape  of  the  pods,  the  tallness  or  shortness  of  the  bodies. 
This  gave  rise  to  what  is  known  as  the  law  of  unit  char- 
acters, for  it  appears  that  our  heredity  is  made  up  of  unit 
characters,  and  that  when  we  are  like  both  our  fathers  and 
our  mothers  we  have  received  certain  unit  characteristics 
from  each  of  them  and  not  a  blend  of  the  two. 

The  law  of  dominance.  —  He  also  found  that  if  he  crossed 
peas  containing  two  charac- 
ters, such  as  the  yellowness 
and  greenness  of  the  peas 
in  a  pod,  one  character 
always  dominated  over  the 
other  and  would  appear  in 
the  offspring.  The  other 
character,  in  this  case  the 
greenness  of  the  peas,  would 
not  be  lost,  but  would  appear 
in  a  later  generation.  This  is  called  the  law  of  dominance. 
The  law  of  segregation.  —  When  Mendel  bred  yellow 

and  green  peas  he 
found  the  offspring 
all  had  yellow  peas 
in  the  pod.  These 
peas  were  really  hy- 
brids, that  is,  they 
were  the  offspring  of 
two  parents  which 
differed  in  respect 
to  a  certain  unit 
character.  If  these 


This  illustrates  the  law  of  dominance. 
Rough  coat  is  a  dominant  characteris- 
tic. 


This  illustrates  the  law  of  segregation.  Follow  out 
the  crossings  of  the  D  hybrids  to  the  F3  genera- 
tion. The  proportion  of  hybrid  to  pure  recessive 
is  3:  1.  Pure  recessives  v»in  always  breed  reces- 
sives  and  dominants  will  breed  dominants. 


hybrids    were    bred 


404        HOW  PLANTS  AND  ANIMALS  IMPROVED 

each  with  another  hybrid  of  the  same  kind,  then  in  the 
next  generation  the  offspring  would  be  produced  in  the 
ratio  of  about  three  yellow  to  one  green,  or  three  dominant 
to  one  recessive.  If  the  hybrid  peas  were  bred  with  a 
green  pea  (a  pure  recessive),  then  the  offspring  would  be 
produced  at  the  rate  of  about  two  dominant  and  two 


T5lack,5moort\. 
\rr 

r 


Bhck.rougK  Black.rough  Black,  rough  Black.  nou^lx. 


_ 
Black.rough  BlacKSnooth  black  .routfh  Black  .smooth. 


_ 

Black.rough  Black.rouph  Albino  .rough  Albino. rougK 


BkckrougK  Blaclc.smoothfllbii>o.TougN  fllbiro .  Smooth. 


Kev  B-  blade  T?-roucd\' 
'' 


b-olbmo   r-5n\cx3tK 


The  inheritance  of  contrasted  characters.  Mendel's  law  shows  that  unit  characters 
are  handed  down  from  parent  to  offspring.  Notice  that  if  we  cross  a  smooth,  black 
guinea  pig  with  a  rough,  white  guinea  pig,  black  and  roughness  of  coat  are  domi- 
nant characters.  In  the  F2  generation  we  find  these  unit  characters  sorted  out  in 
the  proportion  of  9  rough  black,  3  smooth  black,  3  rough  white,  and  i  smooth  white 


recessive.  If  the  hybrid  is  crossed  with  a  pea  of  the  yellow 
variety  (a  dominant)  then  all  dominants  are  produced 
in  the  next  generation.  This  is  called  the  law  of  segrega- 
tion. 

Use  of  this  knowledge.  —  Since  it  is  quite  evident  that  a 
knowledge  of  these  laws  is  of  very  great  importance  to 
plant  and  animal  breeders,  hundreds  of  biologists  are  trying 
to  find  out  new  dominant  and  recessive  characteristics  in 


USE  OF  THIS  KNOWLEDGE 


405 


plants  and  in  animals,  for  it  is  only  by  a  knowledge  of 
these  characteristics  that  intelligent  breeding  of  plants  and 
animals  can  take  place.  Much  can  be  done  with  selection, 
but  by  means  of  a  knowledge  of  Mendel's  law  it  is  quite 
possible  for  those  who  are  trying  to  make  better  plants  and 
animals  to  breed  for  exactly  the  qualities  that  they  wish. 
And  so  the  dairyman  breeds  for  greater  milk  and  cream 
production,  the  hog  raiser  for  heavier  hogs,  the  sheep  grower 
for  more  and  better  wool,  and  the  florist  for  new  and  more 
beautiful  flowers.  Heritable  traits  in  man  as  well  as  in 
plants  and  animals  seem  to  be  subject  to  these  natural 
laws.  One  may  therefore  predict  with  some  degree  of  ac- 
curacy the  characteristics  of  children.  Thus  we  see  that 
the  application  of  all  this  knowledge  is  of  tremendous  con- 
sequence to  the  future  of  the  human  race.  The  following 
tables  show  some  of  the  characteristics  that  have  already 
been  discovered  in  plants  and  animals. 

INHERITED   CHARACTERISTICS   OF   PLANTS 


PLANT 

DOMINANT  CHARACTER 

RECESSIVE  CHARACTER 

Barley 

Beardless 

Bearded 

Corn  (Indian  corn) 

Round  seed 

Wrinkled  seed 

" 

Yellow  grain 

White  grain 

Cotton 

Colored  lint 

White  lint 

Garden  pea 

Tallness 

Dwarf  habit 

" 

Round  seed 

Wrinkled  seed 

" 

Colored  seed  coat 

White  seed  coat 

" 

Yellow  albumin  in 

Green  albumin  in 

cotyledon 

cotyledon 

Sunflower 

Branching  stem 

Non-branching  stem 

Sweet  pea 

Purple  flowers 

White  flowers 

" 

Long  pollen 

Round  pollen 

Thorn  apple 

Prickly  fruit 

Smooth  fruit 

Tomato 

Two-celled  fruit 

Many-celled  fruit 

Wheat 

Beardless 

Bearded 

*  *                                                                                    •' 

Late  ripening 

Early  ripening 

406        HOW  PLANTS  AND  ANIMALS  IMPROVED 


INHERITED    CHARACTERISTICS    OF    ANIMALS 


ANIMAL 

DOMINANT  CHARACTER 

RECESSIVE  CHARACTER 

Canary 

Crested  head 

Plain  head 

Cattle 

Polled  (hornless) 

Horned 

Fowl 

Rose  comb 

Single  comb 

" 

Rumpless 

Rump 

"     white  leghorn 

White 

Colored 

"     another  race 

Colored 

White 

Fruit  fly 

Red  eyes 

White  eyes 

" 

Beaded  wings 

Normal  wings 

" 

Long  wings 

Vestigial  wings 

Guinea  pig 

Colored 

White 

M 

Rough  coat 

Smooth  coat 

Horse 

Bay  coat 

Chestnut  coat 

Mouse 

Normal  movement 

Waltzing  movement 

" 

Colored 

White 

Rabbit 

Short  hair 

Long  hair  (Angora) 

Silkworm 

Yellow  cocoon 

White  cocoon 

Experiment.  —  To  show  how  hybridizing  is  accomplished. 
Materials:    Plants  bearing  flowers.      A    manila   bag.     A   camel's  hair 

brush. 

Method:  Tie  a  manila  bag  over  a  flower  that  is  about  to  open.  Find 
another  flower  that  is  about  to  open,  on  a  plant  of  the  same  family 
though  another  variety  or  preferably  another  species,  and  from  that 
flower  remove  all  the  stamens.  Tie  a  bag  over  it  also.  Why? 

When  the  flower  in 
the  first  bag  opens  trans- 
fer by  means  of  a  small 
camel's  hair  brush  some 
of  the  pollen  to  the 
stigma  of  the  flower 
without  the  stamens. 
Put  the  bag  again  over 
the  second  flower,  plac- 
ing a  label  on  it.  Give 
all  of  your  data. 
Observations:  Why  do  we 

take  so  much   care   in 

Transfer  of  pollen  in  hybridization.  covering  the  flower? 


THE   WORK  OF  SOME   PRACTICAL  BREEDERS      407 


Why  such  care  in  the  transfer  of  pollen  ? 

Remember  that  as  a  result  of  this  transfer  the  sperm  cell  of  one 
flower  may  unite  with  the  egg  cell  of  another  having  quite  different 
qualities. 
Conclusions:  What  is  the  use  of  hybridization  ? 

The  work  of  some  practical  breeders.  —  In  this  coun- 
try the  name  of  Luther  Burbank  stands  prominently  as  a 
great  creator  of  plant  life.  While  Burbank  has  produced 
many  wonderful  plants  it  must  not  be  thought  that  he 


Steps  in  budding,  a,  twig  having  suitable  buds  to  use :  b,  method  of  cutting  out  bud; 
c,  how  bark  is  cut;  d,  how  the  bark  is  opened;  (-.inserting  the  bud;  /,  the  bud  in 
place;  g,  the  bud  properly  bound  in  place. 

has  produced  any  new  unit  characters.  He  really  selects 
from  a  great  number  of  plants  a  few  that  have  varied  in 
such  a  way  as  to  display  prominently  some  unit  character 
or  combination  of  unit  characters  which  he  is  desirous  of 
perpetuating.  He  destroys  tens  of  thousands  of  plants 
which  do  not  have  the  desired  characters.  Another  method 
used  by  Burbank  is  that  of  artificial  hybridizing.  By  this 
method  he  carefully  covers  a  flower  on  some  plant  which 


408 


HOW  PLANTS   AND   ANIMALS   IMPROVED 


Position  of  the  scions;  C,  cam- 
bium layer 


he  wishes  to  experiment  with,  and  at  the  proper  time 
cuts  off  the  stamens  before  the  pollen  is  produced.  Then 
he  carefully  dusts  the  stigma  of  the  pistil  with  pollen  from 
another  plant  which  contains  the  qualities  he  wishes  to 

cross  with  the  first 
plant.     If  these  two 
plants  are  near  rela- 
tives then  it  is  likely 
that  the  pollen  will 
grow  and  a  new  va- 
riety   will    be    pro- 
duced.   Among  such 
famous   hybrids  are 
the    "plumcot"     a 
cross     between     an 
apricot  and  a  plum, 
the  "  Climax  "plum, 
a    cross    between    a 
bitter    Chinese    and 
an   edible   Japanese 
plum,  and  his  many 
varieties  of  berries, 
particularly      the 
"  Lawton  "      black- 
berry and  the  logan- 
berry.    Another  new  cross  is  the  spineless  cactus,  which 
promises  to  be  a  wonderful  food  plant  for  cattle  in  the 
desert  regions  where  grass  cannot  be   grown.     Most  of 
Burbank's   varieties   thus   produced  will  not  grow    from 
seeds,  but  are  produced  asexually,  by  grafting  or  budding, 
as  illustrated  in  the  diagrams  (pages  407,  408). 
The  work  of  the  Department  of  Agriculture.  —  One  of 


Scion 


Scions  in  the  cleft 


Cleft  graft 
complete 


Grafting.  The  scion  is  taken  from  a  tree  having  the 
kind  of  fruit  desired  and  placed  in  a  tree  of  the 
same  species  as  suggested  above. 


WORK  OF  THE  DEPARTMENT  OF  AGRICULTURE      409 


the  greatest  factors  in  the  production  of  more  and  better 
crops  in  this  country  is  the  Department  of  Agriculture. 
Not  only  are  they  doing  wonderful  work  with  methods 
such  as  have  been  de- 
scribed, but  they  have 
perfected  new  ways  of 
grafting  and  budding. 
If  a  tree,  for  example, 
produces  a  kind  of  fruit 
which  is  of  excellent 
quality,  it  is  quite  pos- 
sible to  insert  a  bud 
from  this  tree  into 
another  strong  tree  of 
the  same  species  that  is 
not  a  good  fruit  pro- 
ducer, and  thus  get  the 
desired  fruit.  A  T- 
shaped  incision  is  cut  in 
the  bark,  a  bud  from  the 
tree  bearing  the  desired 
fruit  is  placed  in  the  cut 
and  bound  in  place. 
When  this  bud  grows 
]ater  its  branches  will 
bear  the  desired  fruit. 

In  somewhat  the  same 
way    grafting    is    done. 

In  this  Case  a  Small  por-  Experimental  breeding  plots. 

tion  of  the  stem  of  a  tree  is  fastened  into  another  tree 
of  the  same  species  so  that  the  barks  of  both  come 
together.  This  allows  the  food  to  pass  from  the  tree 


410        HOW  PLANTS  AND  ANIMALS  IMPROVED 

into    the    grafted    stem,    and    thus    the    stem   is    nour- 
ished. 

The  Department  of  Agriculture  is  also  doing  remark- 
able work  in  the  application  of  Mendel's  law.  They 
have  succeeded  in  breeding  wheat  with  certain  unit  char- 
acters which  enable  it  to  resist  cold,  frost,  and  rust.  Many 
cattle  are  now  being  bred  for  immunity  against  certain 
diseases.  This  work  of  the  Department  of  Agriculture 
bids  fair  to  be  the  most  successful  and  important  that  it 
has  yet  done.  The  state  departments  of  agriculture  also 
have  developed  greatly  and  in  many  states  are  the  chief 
sources  of  help  to  the  farmer.  They  are  developed  in  con- 
nection with  the  state  agricultural  schools  and  universities 
and  do,  by  means  of  their  experimental  farms,  much  to 
make  plant  and  animal  products  more  useful  to  man. 

REFERENCE  BOOKS 

Bailey,  Plant  Breeding.     The  Macmillan  Company. 

Caldwell  and  Eikenberry,  General' Science.     Ginn  and  Company. 

Coulter,  Fundamentals  in  Plant  Breeding.  (For  teachers.)  D.  Appleton  and 
Company. 

Downing,  The  Third  and  Fourth  Generation.  (For  teachers.)  University  of  Chicago 
Press. 

Gibson,  Blossom    Hosts  and  Insect  Guests.     Newson  and  Company. 

Gruenberg,  Elementary  Biology.     Ginn  and  Company. 

Harwood,  New  Creations  in  Plant  Life.     The  Macmillan  Company. 

Hodge,  Civic  Biology.     Ginn  and  Company. 

Hunter,  A  Civic  Biology.     American  Book  Company. 

Hunter,  Laboratory  Problems  in  Civic  Biology.     American  Book  Company. 

Jewett,  The  Next  Generation.     Ginn  and  Company. 

Jordan,  The  Heredity  of  Richard  Roe.     American  Unitarian  Ass'n. 

Moore  and  Halligan,  Plant  Production.     American  Book  Company. 

Smith  and  Jewett,  Introduction  to  the  Study  of  Science.     The  Macmillan  Company. 

Van  Buskirk  and  Smith,  The  Science  of  Everyday  Life.  Houghton  Mifflin  Com- 
pany. 

Wilson,  The  Cell  in  Development  and  Inheritance.  (For  teachers.)  Columbia  Uni- 
versity Press. 


CHAPTER  XXVI 
HOW  THE   HUMAN   RACE   HAS   PROGRESSED 

Problems.  —  i.  To  learn  how  man  handed  down  knowl- 
edge. 

2.  To  understand  the  meaning  of  the  triangle  of  life. 

3.  To  learn  the  meaning  of  feeble-mindedness. 

4.  To  understand  why  "  blood  will  tell" 

5.  To  understand  the  meaning  of  eugenics  and  euthenics. 

Experiment.  —  i.  To  determine  some  means  of  bettering  the  human 
race  physically  and  mentally. 

Project  I.  —  To  MAKE  A  STUDY  OF  THE  HEREDITY  OF  MY  OWN 
FAMILY. 

a.  Obtain  from  the  laboratory  of  the  Carnegie  Institute,  Cold 
Spring  Harbor,  New  York,  material  for  the  study  of  your  own  family 
history. 

b.  Get  all  the  data  you  can  from  parent,  grandparent,  and  other 
relatives  and  construct  a  chart  such  as  is  shown  in  some  of  the  illus- 
trations in  this  chapter. 

c.  Prepare  a  report  of  the  findings. 

Project  II.  —  To  MAKE  A  STUDY  OF  ALL  THE  CONTROLLABLE  FAC- 
TORS IN  MY  ENVIRONMENT  WHICH  WILL  HELP  OR  HINDER  ME  IN  LIFE. 

The  beginning  of  civilization.  —  We  have  already  told 
the  story  of  man's  early  life  on  the  earth.  It  is  indeed 
a  far  cry  from  the  cave  man  living  by  the  strength  of 
his  arm  and  spear  to  the  civilized  man  of  to-day.  We 
have  progressed  greatly  and  the  civilized  earth  is  a  much 
better  place  for  habitation  than  it  was  in  the  days  when 
man  wandered  without  a  fixed  abode.  It  is  also  a  much 

411 


412     HOW  THE  HUMAN   RACE  HAS   PROGRESSED 


safer  place  than  in  the  days  of  Greece  and  Rome  with  all 
their  vaunted  civilization.  How  is  it  that  man  has  im- 
proved so  greatly? 

Man  learns  from  experience.  —  Man  differs  greatly  from 
the  lower  animals  in  one  respect.  They  can  learn  from 
experience  but  they  cannot  tell  others.  A  little  chick, 
for  example,  just  out  of  the  shell,  picks  at  a  badly  tasting 
worm  and  gets  an  impression  that  lasts  it  through  its 
life.  It  will  probably  never  pick  up  such  a  worm  again. 
But  all  other  chicks  will  have  to  learn  all  this  over  again 
by  themselves.  On  the  other  hand,  man  learns  not  only 
to  profit  by  experience  but  to  teach  what  he  has  learned 

to  others  and  thus  hand  the 
knowledge  down  to  the  next  gen- 
eration. We  cannot  hand  down 
by  heredity  the  knowledge  we 
have  gained  in  this  life,  but  we 
can  teach  others  and  they  can 
pass  on  the  information  they 
have  acquired. 

Knowledge  that  concerned 
the  making  of  fire.  —  The 
making  of  fire  was  so  impor- 
tant a  process  that  it  was 
doubtless  considered  in  the  re- 
lation of  a  religious  rite  or 
ceremony,  and  by  such  means 
it  was  impressed  upon  the 

youths  of  the  tribe.  The  boys  of  the  tribe  learned  from 
their  fathers  how  to  make  spears,  bows  and  arrows,  and 
nets  with  which  to  catch  fish.  Women  in  primitive  life 
doubtless  did  all  of  the  household  work.  They  planted 


This  shows  how  an  Australian  na- 
tive kindles  a  fire.  Our  remote 
ancestors  used  similar  methods. 
Some  American  Boy  Scouts  can 
kindle  a  fire  in  this  way. 


HOW  CIVILIZED  LIFE  HAS  DEVELOPED 


413 


and  tilled  little  fields  in  order  to  keep  body  and  soul  to- 
gether when  the  hunting  and  fishing  gave  no  return. 
Necessity  doubtless  prompted  them  to  make  vessels  of 


Primitive  stone  tools  and  weapons 

soapstone  or  other  soft  stone  in  which  they  could  cook. 
They  learned  to  use  fibers  and  weave  them  into  rude 
clothes  when  skins  were  not  obtainable.  They  raised  their 
children  and  taught 
the  girls  the  same 
things  that  they  had 
learned  to  do. 

How  civilized  life 
has  developed.  - 
Early  in  the  life 
of  man  the  clan  or 
tribe  played  an  im- 
portant part.  Grad- 
ually people  began 
to  live  together  in 

communities  for  mutual  protection.  Inhabitable  areas 
began  to  be  used  by  more  and  more  people.  Regions  of 
fertility  came  to  be  seized  upon  by  clans  or  tribes.  Wars 
thus  developed  for  the  possession  of  these  areas  or  in  de- 
fense of  them  by  the  people  who  lived  there.  All  this  led 
to  strong  tribal  feeling.  It  also  led  to  another  develop- 


Primitive  "  household  "  work. 


414     HOW  THE  HUMAN  RACE  HAS  PROGRESSED 

ment  —  that  of  the  strong  man  in  the  tribe  as  leader  or 
chief,  and  from  this  came  the  further  one,  that  the  son  of 
the  chief  ought  to  continue  in  power.  Thus  government 
by  a  few  rather  than  by  many  developed. 

Civilization  and  science.  —  In  the  early  days  of  civiliza- 
tion, communication  and  transportation  were  crude  and 
difficult.  Superstition  and  lack  of  knowledge  made  people 
incapable  of  coping  with  famine  or  disease.  But  as  time 
went  on  man  became  more  and  more  scientific  in  his  way  of 
doing  things  and  in  his  method  of  thought.  To-day  we 
live  in  an  age  of  science.  The  World  War  in  spite  of  its 
evil  has  shown  a  good  side  since  it  has  drawn  men  and 
women  the  civilized  world  over  towards  scientific  thinking 
in  the  solution  of  their  problems.  It  has  also  led  to  co- 
operation rather  than  antagonism.  Witness  the  work  done 
during  the  World  War  by  Catholic  and  Protestant  together, 
by  the  Red  Cross  at  home  and  abroad,  and  by  the  Hoover 
committee  for  the  relief  first  of  the  Belgians  and  then  for  the 
saving  of  lives  in  other  afflicted  parts  of  Europe. 

In  life,  however,  we  must  have  competition  to  stimulate 
us  as  well  as  cooperation  to  make  growth  possible.  Science 
is  showing  how  competition  and  cooperation  may  go  hand 
in  hand.  It  is  directing  the  work  in  great  factories,  making 
working  conditions  there  safer  and  better,  and  increasing  the 
output  by  means  of  improved  machinery.  Science  is  help- 
ing man  through  cooperation  in  the  saving  of  human  lives, 
in  better  sanitation  and  hygiene  in  the  home  and  in  the 
community.  It  is  showing  us  better  methods  of  work  in  the 
hospitals  and  in  the  sanatoria.  It  is  giving  us  better  prisons 
and  methods  of  dealing  with  prisoners.  It  is  making  our 
teachers  and  physicians  better  equipped  and  more  capable 
of  coping  with  problems  based  on  science ;  it  is  becoming 


HEREDITY  IN  MAN 


415 


a  part  of  the  working  knowledge  of  every  boy  and  girl, 
as  well  as  father  and  mother,  thus  to  be  passed  along  to 
the  next  generation. 

Triangle  of  life.  —  A  good  deal  has  been  said  and  written 
upon  the  question, "  Which  is  the  more  important  for  a  per- 
son, his  heredity  or  his  environment  ?  "  As  a  matter  of  fact 
the  life  of  each  one  of  us  is  influenced  by  three  great  factors ; 
these  are  heredity  or  what 
we  are,  environment  or  what 
we  have,  and  training  or 
what  we  do.  We  have  shown 
in  the  previous  chapters  of 
this  book  how  important  our 
environment  is  and  how 
much  is  being  done  to  im- 
prove it.  In  the  first  part 
of  this  chapter  we  have  seen 
how  important  training  has 
been  and  still  is  in  the  lives 
of  people.  Let  us  now  ask 

ourselves  the  question,  "  What  part  does  heredity  play 
in  our  lives?"  Knowledge  that  the  race  is  gradually 
changing,  that  there  is  a  constant  growth  or  evolution 
makes  us  ask,  "  Can  these  laws  of  heredity  of  which 
we  learned  in  the  last  chapter  be  applied  to  the  human 
race?" 

Heredity  in  man.  —  We  have  already  seen  that  the 
chromosomes  which  are  believed  to  be  the  bearers  of  the 
determiners  of  the  heredity  qualities  are  present  in  the 
cells  of  certain  flowers  and  of  frogs.  Are  they  present 
in  the  cells  of  man  as  well  ?  It  has  been  found  that  chromo- 
somes are  present  in  the  germ  cells  of  all  plants  and  animals 


The  triangle  of  life. 


416     HOW  THE  HUMAN  RACE  HAS   PROGRESSED 


Wrvi-be,  Eye. 

| 
Tformal  Wing 

VermillionlS- 


"Normal  Wmg 


-ReoL. 
WimaturaWing 


ItUaimentary  Wing  ( 
forked.  Bristles' 
Complete.  Eye ' 


.  "Bristl 


Bccr> 


and  differ  in  number  in  different  species.  In  the  little 
worm  called  ascaris  and  in  the  fruit  fly,  there  are  four 
chromosomes  in  one  germ  cell.  In  the  mosquito  (culex) 
there  are  six,  in  the  rat  sixteen,  in  the  frog  twenty-four, 

in  man  forty-seven,  and 
in  woman  forty-eigLt. 
In  certain  crustaceans 
there  are  over  one  hun- 
dred and  fifty,  while  in 
one  tiny  animal  there 
are  believed  to  be  as 
many  as  sixteen  hun- 
dred. It  is  therefore 
reasonable  to  believe 
that  the  chromosomes 
in  the  human  animal 
are  similar  in  structure 
and  in  function  to  those 
of  lower  animals.  Professor  Morgan  at  Columbia  Univer- 
sity came  to  believe,  as  a  result  of  his  studies  with  a  tiny 
fruit  fly,  that  the  chromosomes  actually  were  made  up  of 
unit  characters  and  that  these  characters  were  often  linked 
together  in  the  same  sex  and  were  handed  on  together. 
This  suggests  a  makeup  of  chromosomes  as  is  shown  in 
the  diagram  above. 

It  can  easily  be  seen  that  with  forty-eight  chromosomes 
it  would  be  a  very  difficult  matter  for  us  to  follow  up  just 
which  traits  or  structures  were  dominant  and  which  re- 
cessive, since  so  many  different  combinations  of  char- 
acters are  possible.  However,  a  number  of  characteristics 
have  been  determined  already,  as  the  following  table 
shows. 


This  section  through  two  chromosomes  shows 
how  it  might  be  possible  to  prove  that  differ- 
ent chromosomes  contain  separate  unit  char- 
acters. 


THE  HEREDITY  OF  CIVILIZED   MAN 
INHERITED    CHARACTERISTICS   OF   MAN 


417 


DOMINANT  CHARACTER 


RECESSIVE  CHARACTER 


Eyes: 

Brown 

"Night-blinded" 

Pigmented  iris 
Hair: 

Beaded 

Curly 

Dark 
Limbs  and  digits: 

Abnormal  shortness 

Abnormal  number  of  digits 
General: 

Nervous  temperament 

Normal-minded 

Normal  color 


Eyes: 

Blue 

Normal  sight  at  dusk 

No  pigment  in  iris 
Hair: 

Even 

Straight 

Light 
Limbs  and  digits: 

Normal  length 

Normal  number  of  digits 
General: 

Phlegmatic  temperament 

Feeble-minded 

Albinism 


Improvement  of  the  human  stock.  —  It  is  quite  evident 
from  what  we  have  seen  that  through  personal  hygiene, 
through  improvement  of  the  environment,  a  healthier  and 
stronger  race  has  been  brought  about.  But  if  we  study 
the  records  which  come  down  to  us  from  the  history  of 
certain  royal  families,  of  certain  well-known  families  in 
this  country  and  Europe,  and  in  studies  made  of  other 
families  which  through  misfortune  have  become  a  burden 
on  society,  we  find  that  breeding  in  man  must  be  taken 
into  account  as  well  as  in  plants  and  animals. 

The  heredity  of  civilized  man.  —  A  number  of  years  ago 
there  lived  in  an  isolated  part  of  New  York  state  a  family 
of  ne'er-do-wells.  This  family,  known  as  the  Jukes,  has 
been  carefully  studied.  Up  to  1915  there  were  2094 
members.  Of  this  number  1600  living  at  present  are 
feeble-minded  or  epileptic.  There  have  been  310 
paupers;  over  300  immoral  women;  140  criminals,  of 

H.  W.  CIV.  SCI.  COMM. 27 


4i8     HOW  THE  HUMAN  RACE  HAS  PROGRESSED 


whom  7  were  murderers.  Not  a  soldier  has  appeared 
in  the  family  and  no  one  of  them  has  had  a  common  school 
education.  Only  20  have  learned  a  trade  and  10  of  these 
learned  it  while  in  prison.  The  family  has  cost  society 
over  $2,500,000  up  to  the  present  time.  And  why?  Be- 
cause the  original  stock  was  feeble-minded  and  intermar- 
riages have  handed  down  the  feeble-mindedness  to  other 
generations.  Another  case  is  that  of  the  Kallikak  family. 


OOQQdBBQQ 


The  family  pedigree  of  the  "  Kallikak  "  family.     Is  feeble-mindedness  handed  down 

by  heredity? 

This  family  has  been  traced  back  to  the  time  of  the  War 
of  the  Revolution  when  a  soldier  named  Martin  Kallikak 
had  a  feeble-minded  son  by  a  feeble-minded  girl.  Up  to 
the  present  time  there  have  been  480  descendants  from 
this  boy.  Of  these  33  were  sexually  immoral,  24  con- 
firmed drunkards,  3  epileptics,  and  143  feeble-minded. 
The  young  man  who  started  this  terrible  line  of  immorality 
and  feeble-mindedness  later  married  a  normal  Quaker 
girl  of  good  family.  From  this  couple  a  line  of  496  de- 
scendants have  come  in  which  there  are  no  cases  of  feeble- 


PARASITISM  AND  ITS  COST  TO  SOCIETY        419 

mindedness.  Feeble-mindedness  is  thus  seen  to  act  as  a 
recessive  Mendelian  characteristic,  and,  as  a  study  of  the 
diagram  shows,  if  one  feeble-minded  person  marries  another 
all  their  offspring  are  sure  to  be  feeble-minded. 

Parasitism  and  its  cost  to  society.  —  If  this  were  but 
one  case  it  would  be  bad  enough,  but  there  are  over  200,000 
feeble-minded  persons  in  the  United  States  to-day.  These 
persons  spread  disease,  crime,  and  immorality  in  all  parts 
of  the  country,  principally  because  they  know  no  better. 
Just  as  certain  plants  or  animals  become  parasitic  on  others 
so  these  people  have  become  parasites  on  society.  Largely 
for  them  the  asylum  and  the  poorhouse  exist.  They  take 
from  society  but  they  give  nothing  in  return.  In  the  valley 
of  Aosta  a  few  years  ago  there  existed  a  number  of  idiotic 
folk  known  as  cretins.  Probably  over  fifty  per  cent  of  the 
inhabitants  of  this  little  mountain  valley  were  so  affected. 
But  thanks  to  wise  planning  these  idiots  were  segregated, 
the  males  in  one  asylum  and  the  females  in  another.  Since 
that  time  the  race  of  cretins  has  gradually  died  out  and  one 
scarcely  ever  sees  any  of  them  now.  This  is  the  only  means 
by  which  feeble-mindedness  can  be  eventually  blotted  out 
from  the  earth. 

Experiment.  —  To  determine  some  means  of  bettering  the  human  race 
physically  and  mentally. 

Materials:  Charts  adapted  from  Davenport,  Goddard,  or  other  authors 
showing  the  heredity  of  genius,  mental  traits,  feeble-mindedness, 
epilepsy,  etc. 

Method:  Make  a  careful  study  of  the  charts  to  answer  the  following 
questions. 

Observations:  Are  mental  traits  handed  down  from  one  generation  to 
another?  Is  artistic  ability  handed  down?  Is  musical  ability  handed 
down?  If  one  party  to  a  marriage  is  feeble-minded  are  any  of  the  chil- 
dren likely  to  be  feeble-minded?  If  both  parties  to  the  marriage  are 
feeble-minded  what  is  the  probability  of  feeble-minded  children?  Does 


420     HOW   THE   HUMAN  RACE  HAS   PROGRESSED 


feeble-mindedness  seem  to  be  a  dominant  or  recessive  character?     Ex- 
plain. 

Coticlusions:  i.   Is  it  possible  to  better  heredity  through  careful  mating? 
2.   Should  feeble-minded  persons  be  allowed  to  marry? 

The  inheritance  of   moral  and  mental  characteristics. 

—  Fortunately,  the  bad  side  of  heredity  is  not  the  only 
one.  A  study  of  certain  notable  families  has  proved  that 
genius  and  mental  traits  are  also  handed  down.  An  in- 


JfarrordL 
ith  jft-B  ««0«A  wmultanee 


All  •mediocre -,Tione  <f  the  progeny  coera 
above     never o^e  talent  and  avxnctcter 


666666666666 


Jonathan    £<JLw<xrA* 

On.  cf  •*«  UTorUft  Greof««t  Intellects 
ftWSa«r*.  'Prirvc.to.-  ColUy. 


In  1900.  1394  descenders 
located  and.  ttej&lowmg/acts  not«a,: 

Cdlerfte  presidents  13  Vjce-pres  /US-  1 
College  P'-qffc.aor,*  65  U-5-SeKatorj  3 
Doctoi4/  60  Judg-es  30 

ClCTtfVvnen  miJJioiwries  100    Moldera  hhafees  80 
MeOTinOxflmy.Navy  75 
Bmin^t    au^or/  60 
Lawr-r^  100 

•^  Several  Gorcf  TVOT«» 


teresting  example  is 
seen  in  the  Darwin- 
Wedgewood  family  in 
England.  In  five  gen- 
erations of  this  family 
out  of  24  men  17  have 

The  famUypedigree  of  the  Edwards  family      ,  .     . 

been  noted  in  science 

or  in  letters.  In  this  country  the  Jonathan  Edwards  family 
has  been  a  notable  example.  Out  of  1394  descendants  there 
have  been  13  college  presidents,  75  army  officers,  100  lawyers 
and  ministers,  more  than  60  authors,  60  physicians,  295  col- 
lege graduates,  and  not  a  single  pauper.  The  following 
extract  is  taken  from  Davenport's  "  Heredity  in  Relation 
to  Eugenics."  In  1667  Elizabeth  Tuttle,  "of  strong 


THE  MEANING  OF  EUGENICS  421 

will,  and  of  extreme  intellectual  vigor,  married  Richard 
Edwards  of  Hartford,  Conn.,  a  man  of  high  repute  and 
great  erudition.  From  their  one  son  descended  another 
son,  Jonathan  Edwards,  a  noted  divine,  and  president  of 
Princeton  College.  Of  the  descendants  of  Jonathan 
Edwards  much  has  been  written ;  a  brief  catalogue  must 
suffice:  Jonathan  Edwards,  Jr.,  president  of  Union  Col- 
lege; Timothy  Dwight,  president  of  Yale;  Sereno  Ed- 
wards Dwight,  president  of  Hamilton  College;  Theodore 
Dwight  Woolsey,  for  twenty-five  years  president  of  Yale 
College ;  Sarah,  wife  of  Tapping  Reeve,  founder  of  Litch- 
field  Law  school,  herself  no  mean  lawyer ;  Daniel  Tyler,  a 
general  in  the  Civil  War  and  founder  of  the  iron  industries 
of  North  Alabama ;  Timothy  Dwight,  second,  president  of 
Yale  University  from  1886  to  1898;  Theodore  William 
Dwight,  founder  and  for  thirty- three  years  warden  of 
Columbia  Law  School ;  Henrietta  Frances,  wife  of  Eli 
Whitney,  inventor  of  the  cotton  gin,  who,  burning  the 
midnight  oil  by  the  side  of  her  ingenious  husband,  helped 
him  to  his  enduring  fame ;  Merrill  Edwards  Gates,  presi- 
dent of  Amherst  College ;  Catherine  Maria  Sedgwick,  of 
graceful  pen;  Charles  Sedgwick  Minot,  authority  on 
biology  and  embryology  in  the  Harvard  Medical  School; 
Edith  Kermit  Carow,  wife  of  Theodore  Roosevelt;  and 
Winston  Churchill,  the  author  of  "  Coniston  "  and  other 
well-known  novels." 

The  meaning  of  eugenics.  —  The  above  paragraphs 
show  us  that  blood  will  tell  or  rather,  to  put  it  scientifi- 
cally, "  that  the  chromosomes  will  tell  the  story."  It  is 
evident  that  if  the  race  is  to  be  improved,  we  must  im- 
prove the  stock.  This  is  to  be  done  in  the  same  way  that 
we  would  work  on  animals  or  plants,  that  is,  we  must  check 


422     HOW  THE  HUMAN  RACE  HAS  PROGRESSED 

the  reproduction  of  the  poorest  strains  and  mate  the 
individuals  of  the  strongest  stock.  Eugenics  is  the  science 
of  improving  the  human  race  by  better  heredity. 

The  meaning  of  euthenics.  —  People  to-day  all  over 
the  civilized  world  have  a  much  better  chance  than  those 
of  a  few  years  ago.  The  housing  conditions  as  late  as 
1850  in  London  and  other  large  cities  were  disgraceful 
but  are  now  being  gradually  remedied.  For  example, 
a  report  by  Dr.  Havelock  Ellis  tells  us  that  in  one  of  the 
slums  of  London,  a  part  called  Bethnal  Green,  in  1848  many 
of  the  workmen's  homes  were  mere  huts,  small  houses  or 
sheds  never  intended  for  human  habitation.  There  were 
thirty-three  miles  of  streets  and  more  than  one  hundred 
of  by-ways,  only  a  few  miles  of  which  were  paved.  There 
were  few  if  any  sewers.  Refuse  and  filth  were  dumped 
into  the  street  and  accumulated  there,  for  the  entire  street- 
cleaning  department  of  this  part  of  London  consisted  of 
thirteen  worn-out  old  men  who  could  just  about  cover  the 
territory  every  three  months.  It  goes  without  saying  that 
with  such  conditions  pestilence  and  death  stalked  hand  in 
hand.  A  few  years  ago  child  labor  was  permitted  every- 
where. It  amounted  indeed  to  virtual  slavery  in  many 
places.  Children  worked  long  hours  under  conditions 
which  were  unfit  even  for  pigs.  But  to-day  laws  have  been 
made  which  prevent  any  such  unfair  treatment  of  children. 
Civilized  society  would  not  permit  the  conditions  which 
formerly  existed  in  the  London  slums.  A  city  which  allows 
foul  tenements,  narrow  streets,  and  crowded  slums  to  exist 
will  spend  more  than  its  share  for  police  protection,  for 
charity,  and  for  hospitals.  Euthenics  is  the  science  of  the 
betterment  of  the  environment.  It  is  another  factor  in  the 
making  oi  a  stronger  and  healthier  race.  The  world  is 


THE  MEANING  OF  EUTHENICS  423 

growing  better  in  spite  of  what  pessimists  believe.  It  is 
gradually  becoming  a  safer  and  healthier  place  to  live  in. 
The  lives  of  children  are  now  safeguarded  by  purer  milk 
and  better  housing,  by  means  of  public  nurses  and  dispen- 
saries. Our  schools  are  more  useful  and  more  adaptable. 
Our  laws  on  child  labor  are  more  comprehensive  and  helpful. 
Above  all,  both  children  and  parents  are  becoming  better 
educated  in  the  duties  of  good  citizenship  and  healthier 
living.  May  this  book  do  its  part  toward  helping  in  this 
great  work. 

REFERENCE  BOOKS 

Conklin,  Heredity  and  Environment.   (For  teachers.)    Princeton  University  Press. 
Davenport,  Heredity  in  Relation  to  Eugenics.    Henry  Holt  and  Company. 
Downing,  The  Third  and  Fourth  Generation.    (For  teachers.)    University  of  Chicago 

Press. 
Estabrook,  A.  H.,  The  Jukes  in  1915.    Carnegie  Institute,  Washington  Publication 

Number  240,  1916. 
Goddard,  Feeblemindedness,  Its  Causes  and  Consequences.     (For  teachers.)    The 

Macmillan  Company. 
Goddard,  The  Kallikak  Family.    A  Study  in  the  Heredity  of  Feeblemindedness.    The 

Macmillan  Company. 

Gruenberg,  Elementary  Biology.     Ginn  and  Company. 
Guyer,  Being  Well  Born.    Bobbs-Merrill  Company. 
Hodge,  Civic  Biology.     Ginn  and  Company. 
Hunter,  A  Civic  Biology.    American  Book  Company. 
Hunter,  Laboratory  Problems  in  Civic  Biology.     American  Book  Company. 
Richards,   Eulhenics,    The  Science  of  Controllable  Environment.     Whitcomb   and 

Barrows. 
Woods,  Mental  and  Moral  Heredity  in  Royalty.     (For  teachers.)     Henry  Holt  and 

Company. 


INDEX 


NOTE.  —  Numbers  in  heavy-faced  type  refer  to  pages  containing  illustrations  as  well  as 

descriptive  text. 


Accidents,  prevention  of,  259 
Acetylene,  for  illumination,  244 
Adulteration,  184 

Agriculture,  Department  of,  65,  409 
Air,  15,  8 1 

and  weather,  81 

pressure,  82 

saturated,  85 

smoky,  14 
Airplanes,  construction  of,  361 

forerunners  of,  358 

invention  of,  359 

present  and  future,  365 

stability  of,  364 

support  of,  361 

types  of,  361 
Alternating  current,  247 
Anemometer,  95 
Aneroid  barometer,  84 
Animals,  development  in,  396 
Anther,  392 
Anticyclone,  97 
Anti-fly  campaign,  211 
Antitoxin,  for  diphtheria,  199,  200 
Arc  lights,  249 
Artesian  wells,  104,  105 
Artificial  gas,  manufacture  of,  240 
Artificial  selection,  399,  401 
Ashes,  disposal  of,  230 
Atlantic  cable,  374 
Automobile,  338,  339 

Balloons,  354 
Barograph,  85 
Barometer,  83 

aneroid,  84 

experimental,  83 

Bees,  in  relation  to  flowers,  390,  392 
Birds,  57 
Boats,  311 

Breeding,  cause  for  true,  ^01 
Bridges,  335 

principles  of  building,  336 


Bubonic  plague,   and  fleas,  221 
Buoyancy,  311 

Burbank,  Luther,  work  of,  407 
Butter,  test  for,  186 

Canals,  320,  321 

Candies,  test  for,  187 

Carburetor,  343 

Cells,  structure  of,  389 

Chemicals,    used  in   protecting   water 

supply,  153 

Chromosomes,  389,  416 
City,  cooperation  with,  168 

departments,  267 

government  organization  of,  160 

planning,  25 

streets,  163 
Civilization,  beginning  of,  411 

development  of,  413 

science  and,  414 
Climate,  effect  on  community  life,  68 

effect  on  living  things,  68,  69 

ideal,  78 

influence  on  health,  77 

influence  on  industry,  76 
Clouds,  90 

and  rain,  91 

formation  of,  91 
Coal,  60 

mine,  61 

mining  towns,  61 
Coal  gas,  manufacture  of,  241 
Coffee,  test  for,  187 
Cold  storage,  179 
Colleges,  276 
Communication,  early,  368 

means  of,  367 

Communities,     control     for    common 
supplies,  161 

control  of  disease,  193 

farming,  52 

food  supply,  170 

formation  of,  46 


425 


426 


INDEX 


Communities,  government,  26,  160 

history  of,  32 

ideal  community,  n 

kinds  of,  52,  54,  55,  60,  63 

planning,  25 

protection,  254 

resources  of,  48 

schools,  27 

water  supply,  146 
Concrete,  in  road  building,  304 
Cone  clutch,  in  automobiles,  349 
Conservation,  64 
Contagious  disease,  194 

fighting,  197,  210 

recognition  of,  196 

spreading  of,  195,  196,  197,  206,  209 

215,   217,   221,   222 

Cooties,  222 
Copernicus,  35 
Corolla,  392 
Courts,  161 
Crops,  and  snow,  121 

conditions  favorable,  119 
Cross-pollination,  394 
Cyclones,  94,  96 
Cylinders,  in  gas  engines, 

cooling  of,  346 

number  of,  350 

Darwin,  Charles,  400 
Daylight  saving,  72 
Delta,  132,  133 
Determiners,  402 
Development,  in  animals,  396 
Dew,  98 
Diphtheria,  200 
Direct  current,  247 
Dirigible,  357 
Diseases,  193 

bubonic  plague,  221 

carried  in  milk,  176 

contagious,  194,  222 

elephantiasis,  223 

germs  causing,  198 

malaria,  214 

relation  to  insects,  203 

seasonal  variation  in,  177 

sleeping  sickness,  223 

trench  fever,  222 

yellow  fever,  216 
Disinfectants,  198 
Dominance,  Mendel's  law  of,  403 


Drinking  fountain,  278 
Driving,  safe  and  sane,  259,  260 
Drugs,  dangers  of,  189 

habit-forming,  190 
Dry  farming,  123 

Earth,  age  of,  35 

beginning  of  life  on,  32/44 
early  beliefs  of,  35 
formation  of,  34 
Education,  271 

religious  and  moral,  289 
Educational  aids: 

art  museums,  281 

churches,  290 

libraries,  279 

moving  pictures,  285 

schools,  272 
Electric  current,  247 
Electric  lamps,  249,  250,  251 
Electric  railways,  333,  334 
Electricity,  as  motive  power,  317 

consumption  of,  251 

for  street  lighting,  245 

production,  of,  246,  247 
Embryo,  development  of,  395 
Engines,  air-cooled,  346 

gas,  339 

locomotive,  330 

steam,  329 

water-cooled,  347 

Watt's,  328 
Environment,  factors  of,  14 
rosion,  methods  of,  41 

relation  to  rock,  43 

by  water,  39,  134 

by  wind,  43 
Sugenics,  421 
Suthenies,  422 

Experience,  as  a  teacher,  412 
Explosive  mixtures,  342 

farming,  5 

communities,  52 

dry,  123 

relation  to  industries,  53 
reeble-mindedness,  418 
ertilization,  393 
rilters  and  filter  beds,  150,  151 

removal  of  impurities,  152 
?ire  alarm  system,  263 

department,  163,  254,  260 


INDEX 


427 


Fire,   equipment,  255,   260,   261,   262, 
263,  264,  265,  266 

making  of,  412 
protection,  162,  103,  205 
regulations,  267 
traffic  regulations,  264 
Fisheries,    and    fishing    communities, 

55,  56 

Fleas,  in  relation  to  bubonic  plague,  2  2 1 
Flies,  as  disease  carriers,  206,  208 

fighting  flies,  210 

life  habits  of,  205,  207 

relation  to  food,  204 
Floods,  75,  129,  137 

regulation  of,  135 
Flowers,  relation  to  bees,  390,  392 

structure,  391 
Fly-traps,  211 
Fly-wheel,  use  of,  345 
Food,  adulteration  of,  184 

cold  storage,  178 

flies  and,  205 

in  a  store,  180 

inspection  of,  165 

protection  of,  171,  179,  182 

tests  for  purity,  186,  187,  188 
Food  and  Drugs  Act,  182 
Force  pump,  262 
Forestry,  140 
Forests,  destruction  of,  139 

forest  industries,  54,  55 

in  United  States,  137,  138 

protection  of,  140 

regulation  and  production  of  water 
supply  by,  134 

relation  of  water  supply  to,  128 

reserves,  141 

uses  of,  136 
Fossils,  45 
Friction,  298 
Frost,  98 
Fumigation,  198 

Garbage,  disposal  of,  22,  230,  231,  232 

reduction  of,  232 
Gas,  and  power,  341 

artificial,  240 

coal,  242 

manufacture  of,  242,  243 

natural,  for  lighting,  240 
Gas  engine,  339 

air-cooled,  346 


tas  engine,  development  of,  339 

gasoline  engine,  339,  343 

number  of  cylinders,  350 

use  of  kerosene  in,  350 

water-cooled,  347 
Gasoline,  342 

engine,  339,  343 
Generator,  247 
Germ  cells,  401,  402 
ilacier,  42 
Government,  city,  160 

community,  26 
Grades  in  a  road,  302 
Gravity,  36 

center  of,  312 

Harbors,  18,  19,  20 
Health,  and  climate,  77 

Department  of,  164 
Heat  and  temperature,  15 
Heliograph  signaling,  370 
Heredity,  and  variation,  398 

of  characteristics,  405,  417,  420 

of  man,  415,  417,  42° 

in  plants  and  animals,  402-406 
Horse  power,  109,  no 
Hospitals,  164,  165 
Houses,  22,  23 
Human  race,  improvement  of,  417,  419 

progress  of,  411 
Humidity,  85 

in  buildings,  86 

measuring,  88,  89 
Hybridization,  406 
Hygrometer,  87,  88 

Ignition,  in  gas  engines,  347 
Immunity  to  disease.  199 
Incandescent  lights,  250 
Industries,  affected  by  climate,  76 

related  to  farming,  53 

related  to  fishing,  55 

related  to  forests,  54 
Inertia,  299 

Insects,  relation  to  disease,  203 
Iron  mining,  59 
Irrigation,  124,  125,  126 

Lake  front,  of  Chicago,  16 
Lakes,  effect  on  climate,  15 
source  of  water  supply,  153 


428 


INDEX 


Lamp  circuits,  251 

Land,  built  by  action  of  water,  132 

Larynx,  368 

Law     and     order,     preservation     of 

257 

Letters,  delivery  of,  372 
Libraries,  279 

maintenance  of,  280 
Life,  beginning  of,  44 

triangle  of,  415 
Light,  18 

acetylene,  244 

electric,  245,  250 

incandescent,  250 

in  signaling,  369 

natural  gas,  240 
Lighting,  of  streets,    236 
Locomotive,  330,  331 

Mail  service,  371 
Malaria,  214 

causes  of,  215 

cure  for,  216 

relation  to  mosquitoes,  215 
Man,  early  life  of,  45,  46 

heredity  in,  415,  417,  420 

progress  of,  411 

Manufacturing  communities,  63 
Meat,  protection  of,  179 
Medical  fakes,  190 
Mendel,  Gregor,  402 

law,  403 

relation  to  heredity,  404 

use  of  his  discovery,  404 
Milk,  173 

diseases  carried  by,  176 

grades  of,  173 

inspection  of,  166,  171 

pasteurizing,  174 

pure,  172,  174 

tests  for  formaldehyde,  188 
Mineral  resources,  58 

coal,  60 

iron  mining,  59 

mining  communities,  60 
Momentum,  345 
Mosquitoes,  213 

community  fighting  against,  220 

extermination  of,  218,  219 

life  history  of,  212 

protection  against,  218,  219 
Moving    pictures,    as    an    educational 


factor,  285 

invention  of,  286 

production  of,  287 

projection  of,  287,  289 
Muffler,  of  automobile,  349 
Museums,  280,  281 
Mutants,  401 
Mutations,  401 

Natural  resources,  48,  49 
Navigation,  320 
Nebula,  33 

theory,  34 
Nectar,  392 
Newspaper,  382 
Newton,  36 
Nucleus,  402 

Oil,  relation  to  community  life,  62 

well,  62 
Ovule,  393 

Parasitism,  419 

Parks,  142,  284 

Patent  medicines,  188 

Periscope,  318,  319 

Petals,  392 

Pictures,  sent  by  wire,  383 

Pistil,  392 

Planets,  33 

Playgrounds,  281,  282 

types  of,  283 
Police,  255 

patrol  signal  system,  256 

work  of  patrolman,  257 
Pollen,  393 
Preservatives,  187 
Pressure,  155 
Protoplasm,  389 
Public  school,  see  Schools 

Quarantine,  193 

Railways,  development  in  U.  S.,  332 

electric,  333,  334 
Rainfall,  17,  73,  98 
Rats,  relation  to  bubonic  plague,  221 
Receiver,  telephone,  379 
Reclamation,  of  swamps,  122 
Recreation,  public,  164,  285 
Reproduction,  asexual,  389 

sexual,  390 


INDEX 


429 


Reservoirs,  use  of,  152 

Rivers,  erosion  by,  ,39 

Roads,  294,  295,  302,  304,  305,  307 

building  material  for,  303 

early  American,  295 

history  of,  294 

loads  drawn  on,  300 

making  of,  303 
Rocks,  38 

changes  in,  43 

kinds  of,  38,  40,  41 

water  a  builder  of,  131 
Rowing,  313,  314 
Rubbish,  collection  of,  231 

Safety  first,  268,  269 
Sailing,  314 
Schools,  27 

buildings  of,  167,  274,  277,  278 

care  of  children  in,  166 

development  of,  272 

importance  of,  27 

kinds  of,  276 

law  relating  to  attendance,  274 

nurse  in,  27 

organization  of,  162 

system  in  city,  273 

technical,  276 

work  of,  275 
Score  card,  use  of,  28 

advantages     in      the     community, 
293 

board  of  health,  203 

care  of  food,  192 

city  water  supply,  158 

climate  and  weather,  101 

environment,  28,  29,  30 

milk,  175 

public  sanitation,  234 

relation  of  water  to  economic  life, 
144 

safeguarding  life  and  property,  270 
Seasons,  cause  of,  69 
Segregation,  Mendel's  law  of,  403 
Selection,  artificial,  399,  401 

natural,  400 
Septic  tank,  227,  228 
Sewage,  22 

city  care  of,  228 

disposal  into  rivers,  225 

farms,  228 

septic  tank,  227,  228 


Sewer  system,  purpose  of,  225 
Signals,    as   a    means   of    communica 
tion,  368 

by  ear,  370 

by  light,  369 
Skiing,  17,  18 
Smoke  consumer,  14 
Snow,  in  relation  to  crops,  121 
Soil,  21,  44 

Sound,  production  of,  368 
Spark,  in  gas  engine,  348 
Speaking  tubes,  371 
Sperm  cell,  393 
Springs,  104 

Sprinkler,  automatic,  265,  266 
Stability,  of  airplanes,  364 

of  boats,  311 
Stamens,  392 
Steam,  use  of,  315,  326 
Steam  engine,  327 

early,  327 

engine  of  to-day,  329 

model  engine,  327,  328 

testing  of,  326 
Storms,  75,  91 
Street  lighting,  236,  238,  239,  240 

beauty  of,  252 

by  electricity,  245,  252,  253 

history  of,  237 

meaning  of  good,  240 

by  natural  gas,  240 

reasons  for,  239 

sources  of,  238 
Streets,  163 

cleaning  of,  228,  230 
Structure,  of  cells,  389 

of  a  flower,  391 

of  living  things,  388 
Submarine,  317 

Sunlight,  relation  to  climate,  71 
Supplies,  public,  23,  161 
Swamps,  and  mosquitoes,  21,  218,  219 

reclamation  of,  122 

Texas,  city,  271 
Telegraph,  372,  373 

working  of,  374 
Telephone,  376 

receiver,  379 

transmitter,  377 
Telewriter,  383 
Temperature,  in  relation  loplant  life,  37 


430 


INDEX 


Thermograph,  81 

Thermometer,  81,  82,  87 

Tornadoes,  92,  93 

Tractors,  351 

Trade  Routes,  319 

Traffic,  340 

Translantic  flight,  first,  360 

Transformer,  use  of,  248,  249 

Transmission,  348 

Transportation,  changes  in,  324 

through  air,  353 

by  land,  323 

by  rail,  325 

by  water,  308 

Travel,  early  in  America,  323 
Trees,  protection  of,  142 
Trench  fever,  222 
Triangle  of  life,  415 
Turbines,  112 
Tyndall's,  experiment,  387 

Typhoid     germs,     carried     by     flies, 

207 

Unit  characters,  law  of,  402 
Universities,  276 

Vaccination,  200 
Variation,  399 
Velocity,  95 
Vocal  cords,  368 
Volcanoes,  37 

Wastes,  disposal  of,  224 
Water,  appearance  of,  147 

as  a   land  builder,  132 

as  an  underground  solvent,  129 

as  eroding  agent,  39,  131 

in  relation  to  climate,  74 

in  relation  to  food,  115 


Water,  in  relation  to  plant  life,  117 

in  relation  to  power,  119,  102,  105 

in  relation  to  soil,  103 

table,  104 
Water  gas,  243 

Water-holding  power,  103,  134 
Water  power,  19,  106 

relation  to  communities,  112 

utilization  of,  20,  108 
Water  routes,  presence  of,  18 
Water  supply,  116,  146 

drinking  water,  147 

gravity  distribution  of,  155 

lake  water,  153 

of  modern  city,  154 

problems  of,  148 

protection  of,  151,  156 

river,  148 

sources  of,  147 
Water  transportation,  308 
Water  ways,  320,  321 
Water  wheels,  in 
Watt's  engine,  328 
Weather,  15,  80 

maps,  96,  97 
Weather  Bureau,  80,  99 
Wells,  artesian,  104 
Wheels,  on  vehicles 

size  of,  300 

use  of,  298 
Wild  life,  56 
Winds,  causes,  93 

velocity  measurement,  95 
Wireless,  380 
Wood,  uses  of,  138 
Writing,  sent  by  wire,  383 

Yellow  fever, 
relation  to  mosquitoes,  216 


APR   12J934 


LrD  21-100W-7/33 


YB   17566 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 


